Method and apparatus for declaring radio link failure in multiple active bandwidth parts in a wireless communication system

ABSTRACT

A method and an apparatus for declaring radio link failure in multiple active bandwidth parts in a wireless communication system are provided. A wireless device activates a first bandwidth part (BWP) and a second BWP for a serving cell. A wireless device performs a radio link monitoring (RLM) on the first BWP and the second BWP. A wireless device detects a radio link problem on the first BWP. A wireless device decides whether to declare a radio link failure (RLF) for the serving cell based on radio link state of both the first BWP and the second BWP.

BACKGROUND Technical Field

The present disclosure relates to a method and apparatus for declaringradio link failure in multiple active bandwidth parts in a wirelesscommunication system.

Related Art

3rd generation partnership project (3GPP) long-term evolution (LTE) is atechnology for enabling high-speed packet communications. Many schemeshave been proposed for the LTE objective including those that aim toreduce user and provider costs, improve service quality, and expand andimprove coverage and system capacity. The 3GPP LTE requires reduced costper bit, increased service availability, flexible use of a frequencyband, a simple structure, an open interface, and adequate powerconsumption of a terminal as an upper-level requirement.

Work has started in international telecommunication union (ITU) and 3GPPto develop requirements and specifications for new radio (NR) systems.3GPP has to identify and develop the technology components needed forsuccessfully standardizing the new RAT timely satisfying both the urgentmarket needs, and the more long-term requirements set forth by the ITUradio communication sector (ITU-R) international mobiletelecommunications (IMT)-2020 process. Further, the NR should be able touse any spectrum band ranging at least up to 100 GHz that may be madeavailable for wireless communications even in a more distant future.

The NR targets a single technical framework addressing all usagescenarios, requirements and deployment scenarios including enhancedmobile broadband (eMBB), massive machine-type-communications (mMTC),ultra-reliable and low latency communications (URLLC), etc. The NR shallbe inherently forward compatible.

NR is a technology that operates on a very wideband compared with LTE.In order to support flexible broadband operation, NR has the followingdesign principles different from LTE in terms of broadband support.

The ability of the network and the user equipment (UE) to support thebandwidth may be different.

The bandwidth capabilities of the downlink and uplink supported by theUE may be different.

The capabilities of the bandwidths supported by each UE may differ, sothat UEs supporting different bandwidths may coexist within one networkfrequency band.

In order to reduce the power consumption of the UE, the UE may beconfigured with different bandwidth depending on the traffic load stateof the UE, etc.

In order to satisfy the above-mentioned design principles, NR newlyintroduced a concept of bandwidth part (BWP) in addition to carrieraggregation (CA) of existing LTE.

SUMMARY Technical Objects

If a single bandwidth part (BWP) is activated, a wireless device maydeclare the radio link failure (RLF) and initiate the recovery procedure(for example, RRC re-establishment), when the wireless device detectsthe radio link problem for the activated BWP.

When multiple BWPs are activated, a wireless device may need to performthe radio link monitoring (RLM) for each activated BWP.

If a wireless device declares the RLF when the radio link problem isdetected from an activated BWP even though there is another availableactivated BWP, the wireless device would undergo unnecessary serviceinterruption due to the recovery procedure whenever the radio linkproblem happens within a single BWP.

Therefore, studies for declaring radio link failure in multiple activebandwidth parts in a wireless communication system are required.

Technical Solutions

In an aspect, a method performed by a wireless device in a wirelesscommunication system is provided. A wireless device activates a firstbandwidth part (BWP) and a second BWP for a serving cell. A wirelessdevice performs a radio link monitoring (RLM) on the first BWP and thesecond BWP. A wireless device detects a radio link problem on the firstBWP.

A wireless device decides whether to declare a radio link failure (RLF)for the serving cell based on radio link state of both the first BWP andthe second BWP.

In another aspect, an apparatus for implementing the above method isprovided.

Technical Effects

The present disclosure can have various advantageous effects.

According to some embodiments of the present disclosure, a wirelessdevice could declare radio link failure in multiple active bandwidthparts efficiently.

For example, a wireless device could avoid the service interruption timerequired to recover the radio link failure when multiple BWPs areactivated.

For example, a wireless device could declare the radio link failureefficiently only when there is no available active BWP.

For example, a wireless device could change the active BWP efficientlyby informing network of the problematic BWP only when there is noavailable active BWP.

According to some embodiments of the present disclosure, a wirelesscommunication system could provide an efficient solution to a wirelessdevice for declaring radio link failure in multiple active bandwidthparts.

Advantageous effects which can be obtained through specific embodimentsof the present disclosure are not limited to the advantageous effectslisted above. For example, there may be a variety of technical effectsthat a person having ordinary skill in the related art can understandand/or derive from the present disclosure. Accordingly, the specificeffects of the present disclosure are not limited to those explicitlydescribed herein, but may include various effects that may be understoodor derived from the technical features of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example of a communication system to whichimplementations of the present disclosure is applied.

FIG. 2 shows an example of wireless devices to which implementations ofthe present disclosure is applied.

FIG. 3 shows an example of a wireless device to which implementations ofthe present disclosure is applied.

FIG. 4 shows another example of wireless devices to whichimplementations of the present disclosure is applied.

FIG. 5 shows an example of UE to which implementations of the presentdisclosure is applied.

FIGS. 6 and 7 show an example of protocol stacks in a 3GPP basedwireless communication system to which implementations of the presentdisclosure is applied.

FIG. 8 shows a frame structure in a 3GPP based wireless communicationsystem to which implementations of the present disclosure is applied.

FIG. 9 shows a data flow example in the 3GPP NR system to whichimplementations of the present disclosure is applied.

FIG. 10 shows an example of bandwidth part (BWP) configurations to whichimplementations of the present disclosure is applied.

FIG. 11 shows an example of contiguous BWPs and non-contiguous BWPs towhich implementations of the present disclosure is applied

FIG. 12 shows an example of multiple BWPs to which implementations ofthe present disclosure is applied.

FIG. 13 shows an example of a method for declaring radio link failure inmultiple active bandwidth parts in a wireless communication system,according to some embodiments of the present disclosure.

FIG. 14 shows an example of a method for declaring radio link failure inmultiple active bandwidth parts performed by a User Equipment (UE) in awireless communication system, according to some embodiments of thepresent disclosure.

FIG. 15 shows an example of declaring radio link failure in multipleactive bandwidth parts performed by a UE, according to some embodimentsof the present disclosure.

DETAILED DESCRIPTION

The following techniques, apparatuses, and systems may be applied to avariety of wireless multiple access systems. Examples of the multipleaccess systems include a code division multiple access (CDMA) system, afrequency division multiple access (FDMA) system, a time divisionmultiple access (TDMA) system, an orthogonal frequency division multipleaccess (OFDMA) system, a single carrier frequency division multipleaccess (SC-FDMA) system, and a multicarrier frequency division multipleaccess (MC-FDMA) system. CDMA may be embodied through radio technologysuch as universal terrestrial radio access (UTRA) or CDMA2000. TDMA maybe embodied through radio technology such as global system for mobilecommunications (GSM), general packet radio service (GPRS), or enhanceddata rates for GSM evolution (EDGE). OFDMA may be embodied through radiotechnology such as institute of electrical and electronics engineers(IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, or evolved UTRA(E-UTRA). UTRA is a part of a universal mobile telecommunications system(UMTS). 3rd generation partnership project (3GPP) long term evolution(LTE) is a part of evolved UMTS (E-UMTS) using E-UTRA. 3GPP LTE employs

OFDMA in DL and SC-FDMA in UL. LTE-advanced (LTE-A) is an evolvedversion of 3GPP LTE.

For convenience of description, implementations of the presentdisclosure are mainly described in regards to a 3GPP based wirelesscommunication system. However, the technical features of the presentdisclosure are not limited thereto. For example, although the followingdetailed description is given based on a mobile communication systemcorresponding to a 3GPP based wireless communication system, aspects ofthe present disclosure that are not limited to 3GPP based wirelesscommunication system are applicable to other mobile communicationsystems.

For terms and technologies which are not specifically described amongthe terms of and technologies employed in the present disclosure, thewireless communication standard documents published before the presentdisclosure may be referenced.

In the present disclosure, “A or B” may mean “only A”, “only B”, or“both A and B”. In other words, “A or B” in the present disclosure maybe interpreted as “A and/or B”. For example, “A, B or C” in the presentdisclosure may mean “only A”, “only B”, “only C”, or “any combination ofA, B and C”.

In the present disclosure, slash (/) or comma (,) may mean “and/or”. Forexample, “A/B” may mean “A and/or B”. Accordingly, “A/B” may mean “onlyA”, “only B”, or “both A and B”. For example, “A, B, C” may mean “A, Bor C”.

In the present disclosure, “at least one of A and B” may mean “only A”,“only B” or “both A and B”. In addition, the expression “at least one ofA or B” or “at least one of A and/or B” in the present disclosure may beinterpreted as same as “at least one of A and B”.

In addition, in the present disclosure, “at least one of A, B and C” maymean “only A”, “only B”, “only C”, or “any combination of A, B and C”.In addition, “at least one of A, B or C” or “at least one of A, B and/orC” may mean “at least one of A, B and C”.

Also, parentheses used in the present disclosure may mean “for example”.In detail, when it is shown as “control information (PDCCH)”, “PDCCH”may be proposed as an example of “control information”. In other words,“control information” in the present disclosure is not limited to“PDCCH”, and “PDDCH” may be proposed as an example of “controlinformation”. In addition, even when shown as “control information(i.e., PDCCH)”, “PDCCH” may be proposed as an example of “controlinformation”.

Technical features that are separately described in one drawing in thepresent disclosure may be implemented separately or simultaneously.

Although not limited thereto, various descriptions, functions,procedures, suggestions, methods and/or operational flowcharts of thepresent disclosure disclosed herein can be applied to various fieldsrequiring wireless communication and/or connection (e.g., 5G) betweendevices.

Hereinafter, the present disclosure will be described in more detailwith reference to drawings. The same reference numerals in the followingdrawings and/or descriptions may refer to the same and/or correspondinghardware blocks, software blocks, and/or functional blocks unlessotherwise indicated.

FIG. 1 shows an example of a communication system to whichimplementations of the present disclosure is applied.

The 5G usage scenarios shown in FIG. 1 are only exemplary, and thetechnical features of the present disclosure can be applied to other 5Gusage scenarios which are not shown in FIG. 1 .

Three main requirement categories for 5G include (1) a category ofenhanced mobile broadband (eMBB), (2) a category of massive machine typecommunication (mMTC), and (3) a category of ultra-reliable and lowlatency communications (URLLC).

Partial use cases may require a plurality of categories for optimizationand other use cases may focus only upon one key performance indicator(KPI). 5G supports such various use cases using a flexible and reliablemethod.

eMBB far surpasses basic mobile Internet access and covers abundantbidirectional work and media and entertainment applications in cloud andaugmented reality. Data is one of 5G core motive forces and, in a 5Gera, a dedicated voice service may not be provided for the first time.In 5G, it is expected that voice will be simply processed as anapplication program using data connection provided by a communicationsystem. Main causes for increased traffic volume are due to an increasein the size of content and an increase in the number of applicationsrequiring high data transmission rate. A streaming service (of audio andvideo), conversational video, and mobile Internet access will be morewidely used as more devices are connected to the Internet. These manyapplication programs require connectivity of an always turned-on statein order to push real-time information and alarm for users. Cloudstorage and applications are rapidly increasing in a mobilecommunication platform and may be applied to both work andentertainment. The cloud storage is a special use case which acceleratesgrowth of uplink data transmission rate. 5G is also used for remote workof cloud. When a tactile interface is used, 5G demands much lowerend-to-end latency to maintain user good experience. Entertainment, forexample, cloud gaming and video streaming, is another core element whichincreases demand for mobile broadband capability. Entertainment isessential for a smartphone and a tablet in any place including highmobility environments such as a train, a vehicle, and an airplane. Otheruse cases are augmented reality for entertainment and informationsearch. In this case, the augmented reality requires very low latencyand instantaneous data volume.

In addition, one of the most expected 5G use cases relates a functioncapable of smoothly connecting embedded sensors in all fields, i.e.,mMTC. It is expected that the number of potential Internet-of-things(IoT) devices will reach 204 hundred million up to the year of 2020. Anindustrial IoT is one of categories of performing a main role enabling asmart city, asset tracking, smart utility, agriculture, and securityinfrastructure through 5G.

URLLC includes a new service that will change industry through remotecontrol of main infrastructure and an ultra-reliable/availablelow-latency link such as a self-driving vehicle. A level of reliabilityand latency is essential to control a smart grid, automatize industry,achieve robotics, and control and adjust a drone.

5G is a means of providing streaming evaluated as a few hundred megabitsper second to gigabits per second and may complement fiber-to-the-home(FTTH) and cable-based broadband (or DOCSIS). Such fast speed is neededto deliver TV in resolution of 4K or more (6K, 8K, and more), as well asvirtual reality and augmented reality. Virtual reality (VR) andaugmented reality (AR) applications include almost immersive sportsgames. A specific application program may require a special networkconfiguration. For example, for VR games, gaming companies need toincorporate a core server into an edge network server of a networkoperator in order to minimize latency.

Automotive is expected to be a new important motivated force in 5Gtogether with many use cases for mobile communication for vehicles. Forexample, entertainment for passengers requires high simultaneouscapacity and mobile broadband with high mobility. This is because futureusers continue to expect connection of high quality regardless of theirlocations and speeds. Another use case of an automotive field is an ARdashboard. The AR dashboard causes a driver to identify an object in thedark in addition to an object seen from a front window and displays adistance from the object and a movement of the object by overlappinginformation talking to the driver. In the future, a wireless moduleenables communication between vehicles, information exchange between avehicle and supporting infrastructure, and information exchange betweena vehicle and other connected devices (e.g., devices accompanied by apedestrian). A safety system guides alternative courses of a behavior sothat a driver may drive more safely drive, thereby lowering the dangerof an accident. The next stage will be a remotely controlled orself-driven vehicle. This requires very high reliability and very fastcommunication between different self-driven vehicles and between avehicle and infrastructure. In the future, a self-driven vehicle willperform all driving activities and a driver will focus only uponabnormal traffic that the vehicle cannot identify. Technicalrequirements of a self-driven vehicle demand ultra-low latency andultra-high reliability so that traffic safety is increased to a levelthat cannot be achieved by human being.

A smart city and a smart home/building mentioned as a smart society willbe embedded in a high-density wireless sensor network. A distributednetwork of an intelligent sensor will identify conditions for costs andenergy-efficient maintenance of a city or a home. Similar configurationsmay be performed for respective households. All of temperature sensors,window and heating controllers, burglar alarms, and home appliances arewirelessly connected. Many of these sensors are typically low in datatransmission rate, power, and cost. However, real-time HD video may bedemanded by a specific type of device to perform monitoring.

Consumption and distribution of energy including heat or gas isdistributed at a higher level so that automated control of thedistribution sensor network is demanded. The smart grid collectsinformation and connects the sensors to each other using digitalinformation and communication technology so as to act according to thecollected information. Since this information may include behaviors of asupply company and a consumer, the smart grid may improve distributionof fuels such as electricity by a method having efficiency, reliability,economic feasibility, production sustainability, and automation. Thesmart grid may also be regarded as another sensor network having lowlatency.

Mission critical application (e.g., e-health) is one of 5G usescenarios. A health part contains many application programs capable ofenjoying benefit of mobile communication. A communication system maysupport remote treatment that provides clinical treatment in a farawayplace. Remote treatment may aid in reducing a barrier against distanceand improve access to medical services that cannot be continuouslyavailable in a faraway rural area. Remote treatment is also used toperform important treatment and save lives in an emergency situation.The wireless sensor network based on mobile communication may provideremote monitoring and sensors for parameters such as heart rate andblood pressure.

Wireless and mobile communication gradually becomes important in thefield of an industrial application. Wiring is high in installation andmaintenance cost. Therefore, a possibility of replacing a cable withreconstructible wireless links is an attractive opportunity in manyindustrial fields. However, in order to achieve this replacement, it isnecessary for wireless connection to be established with latency,reliability, and capacity similar to those of the cable and managementof wireless connection needs to be simplified. Low latency and a verylow error probability are new requirements when connection to 5G isneeded.

Logistics and freight tracking are important use cases for mobilecommunication that enables inventory and package tracking anywhere usinga location-based information system. The use cases of logistics andfreight typically demand low data rate but require location informationwith a wide range and reliability.

Referring to FIG. 1 , the communication system 1 includes wirelessdevices 100 a to 100 f, base stations (BSs) 200, and a network 300.Although FIG. 1 illustrates a 5G network as an example of the network ofthe communication system 1, the implementations of the presentdisclosure are not limited to the 5G system, and can be applied to thefuture communication system beyond the 5G system.

The BSs 200 and the network 300 may be implemented as wireless devicesand a specific wireless device may operate as a BS/network node withrespect to other wireless devices.

The wireless devices 100 a to 100 f represent devices performingcommunication using radio access technology (RAT) (e.g., 5G new RAT(NR)) or LTE) and may be referred to as communication/radio/5G devices.The wireless devices 100 a to 100 f may include, without being limitedto, a robot 100 a, vehicles 100 b-1 and 100 b-2, an extended reality(XR) device 100 c, a hand-held device 100 d, a home appliance 100 e, anIoT device 100 f, and an artificial intelligence (AI) device/server 400.For example, the vehicles may include a vehicle having a wirelesscommunication function, an autonomous driving vehicle, and a vehiclecapable of performing communication between vehicles. The vehicles mayinclude an unmanned aerial vehicle (UAV) (e.g., a drone). The XR devicemay include an AR/VR/Mixed Reality (MR) device and may be implemented inthe form of a head-mounted device (HMD), a head-up display (HUD) mountedin a vehicle, a television, a smartphone, a computer, a wearable device,a home appliance device, a digital signage, a vehicle, a robot, etc. Thehand-held device may include a smartphone, a smartpad, a wearable device(e.g., a smartwatch or a smartglasses), and a computer (e.g., anotebook). The home appliance may include a TV, a refrigerator, and awashing machine. The IoT device may include a sensor and a smartmeter.

In the present disclosure, the wireless devices 100 a to 100 f may becalled user equipments (UEs). A UE may include, for example, a cellularphone, a smartphone, a laptop computer, a digital broadcast terminal, apersonal digital assistant (PDA), a portable multimedia player (PMP), anavigation system, a slate personal computer (PC), a tablet PC, anultrabook, a vehicle, a vehicle having an autonomous traveling function,a connected car, an UAV, an AI module, a robot, an AR device, a VRdevice, an MR device, a hologram device, a public safety device, an MTCdevice, an IoT device, a medical device, a FinTech device (or afinancial device), a security device, a weather/environment device, adevice related to a 5G service, or a device related to a fourthindustrial revolution field.

The UAV may be, for example, an aircraft aviated by a wireless controlsignal without a human being onboard.

The VR device may include, for example, a device for implementing anobject or a background of the virtual world. The AR device may include,for example, a device implemented by connecting an object or abackground of the virtual world to an object or a background of the realworld. The MR device may include, for example, a device implemented bymerging an object or a background of the virtual world into an object ora background of the real world. The hologram device may include, forexample, a device for implementing a stereoscopic image of 360 degreesby recording and reproducing stereoscopic information, using aninterference phenomenon of light generated when two laser lights calledholography meet.

The public safety device may include, for example, an image relay deviceor an image device that is wearable on the body of a user.

The MTC device and the IoT device may be, for example, devices that donot require direct human intervention or manipulation. For example, theMTC device and the IoT device may include smartmeters, vending machines,thermometers, smartbulbs, door locks, or various sensors.

The medical device may be, for example, a device used for the purpose ofdiagnosing, treating, relieving, curing, or preventing disease. Forexample, the medical device may be a device used for the purpose ofdiagnosing, treating, relieving, or correcting injury or impairment. Forexample, the medical device may be a device used for the purpose ofinspecting, replacing, or modifying a structure or a function. Forexample, the medical device may be a device used for the purpose ofadjusting pregnancy. For example, the medical device may include adevice for treatment, a device for operation, a device for (in vitro)diagnosis, a hearing aid, or a device for procedure.

The security device may be, for example, a device installed to prevent adanger that may arise and to maintain safety. For example, the securitydevice may be a camera, a closed-circuit TV (CCTV), a recorder, or ablack box.

The FinTech device may be, for example, a device capable of providing afinancial service such as mobile payment. For example, the FinTechdevice may include a payment device or a point of sales (POS) system.

The weather/environment device may include, for example, a device formonitoring or predicting a weather/environment.

The wireless devices 100 a to 100 f may be connected to the network 300via the BSs 200. An AI technology may be applied to the wireless devices100 a to 100 f and the wireless devices 100 a to 100 f may be connectedto the AI server 400 via the network 300. The network 300 may beconfigured using a 3G network, a 4G (e.g., LTE) network, a 5G (e.g., NR)network, and a beyond-5G network. Although the wireless devices 100 a to100 f may communicate with each other through the BSs 200/network 300,the wireless devices 100 a to 100 f may perform direct communication(e.g., sidelink communication) with each other without passing throughthe BSs 200/network 300. For example, the vehicles 100 b-1 and 100 b-2may perform direct communication (e.g., vehicle-to-vehicle(V2V)/vehicle-to-everything (V2X) communication). The IoT device (e.g.,a sensor) may perform direct communication with other IoT devices (e.g.,sensors) or other wireless devices 100 a to 100 f.

Wireless communication/connections 150 a, 150 b and 150 c may beestablished between the wireless devices 100 a to 100 f and/or betweenwireless device 100 a to 100 f and BS 200 and/or between BSs 200.Herein, the wireless communication/connections may be establishedthrough various RATs (e.g., 5G NR) such as uplink/downlink communication150 a, sidelink communication (or device-to-device (D2D) communication)150 b, inter-base station communication 150 c (e.g., relay, integratedaccess and backhaul (IAB)), etc. The wireless devices 100 a to 100 f andthe BSs 200/the wireless devices 100 a to 100 f may transmit/receiveradio signals to/from each other through the wirelesscommunication/connections 150 a, 150 b and 150 c. For example, thewireless communication/connections 150 a, 150 b and 150 c maytransmit/receive signals through various physical channels. To this end,at least a part of various configuration information configuringprocesses, various signal processing processes (e.g., channelencoding/decoding, modulation/demodulation, and resourcemapping/de-mapping), and resource allocating processes, fortransmitting/receiving radio signals, may be performed based on thevarious proposals of the present disclosure.

Here, the radio communication technologies implemented in the wirelessdevices in the present disclosure may include narrowbandinternet-of-things (NB-IoT) technology for low-power communication aswell as LTE, NR and 6G. For example, NB-IoT technology may be an exampleof low power wide area network (LPWAN) technology, may be implemented inspecifications such as LTE Cat NB1 and/or LTE Cat NB2, and may not belimited to the above-mentioned names. Additionally and/or alternatively,the radio communication technologies implemented in the wireless devicesin the present disclosure may communicate based on LTE-M technology. Forexample, LTE-M technology may be an example of LPWAN technology and becalled by various names such as enhanced machine type communication(eMTC). For example, LTE-M technology may be implemented in at least oneof the various specifications, such as 1) LTE Cat 0, 2) LTE Cat M1, 3)LTE Cat M2, 4) LTE non-bandwidth limited (non-BL), 5) LTE-MTC, 6) LTEMachine Type Communication, and/or 7) LTE M, and may not be limited tothe above-mentioned names. Additionally and/or alternatively, the radiocommunication technologies implemented in the wireless devices in thepresent disclosure may include at least one of ZigBee, Bluetooth, and/orLPWAN which take into account low-power communication, and may not belimited to the above-mentioned names.

For example, ZigBee technology may generate personal area networks(PANs) associated with small/low-power digital communication based onvarious specifications such as IEEE 802.15.4 and may be called variousnames.

FIG. 2 shows an example of wireless devices to which implementations ofthe present disclosure is applied.

Referring to FIG. 2 , a first wireless device 100 and a second wirelessdevice 200 may transmit/receive radio signals to/from an external devicethrough a variety of RATs (e.g., LTE and NR). In FIG. 2 , {the firstwireless device 100 and the second wireless device 200} may correspondto at least one of {the wireless device 100a to 100 f and the BS 200},{the wireless device 100 a to 100 f and the wireless device 100 a to 100f} and/or {the BS 200 and the BS 200} of FIG. 1 .

The first wireless device 100 may include one or more processors 102 andone or more memories 104 and additionally further include one or moretransceivers 106 and/or one or more antennas 108. The processor(s) 102may control the memory(s) 104 and/or the transceiver(s) 106 and may beconfigured to implement the descriptions, functions, procedures,suggestions, methods and/or operational flowcharts described in thepresent disclosure. For example, the processor(s) 102 may processinformation within the memory(s) 104 to generate firstinformation/signals and then transmit radio signals including the firstinformation/signals through the transceiver(s) 106. The processor(s) 102may receive radio signals including second information/signals throughthe transceiver(s) 106 and then store information obtained by processingthe second information/signals in the memory(s) 104. The memory(s) 104may be connected to the processor(s) 102 and may store a variety ofinformation related to operations of the processor(s) 102. For example,the memory(s) 104 may store software code including commands forperforming a part or the entirety of processes controlled by theprocessor(s) 102 or for performing the descriptions, functions,procedures, suggestions, methods and/or operational flowcharts describedin the present disclosure. Herein, the processor(s) 102 and thememory(s) 104 may be a part of a communication modem/circuit/chipdesigned to implement RAT (e.g., LTE or NR). The transceiver(s) 106 maybe connected to the processor(s) 102 and transmit and/or receive radiosignals through one or more antennas 108. Each of the transceiver(s) 106may include a transmitter and/or a receiver. The transceiver(s) 106 maybe interchangeably used with radio frequency (RF) unit(s). In thepresent disclosure, the first wireless device 100 may represent acommunication modem/circuit/chip.

The second wireless device 200 may include one or more processors 202and one or more memories 204 and additionally further include one ormore transceivers 206 and/or one or more antennas 208. The processor(s)202 may control the memory(s) 204 and/or the transceiver(s) 206 and maybe configured to implement the descriptions, functions, procedures,suggestions, methods and/or operational flowcharts described in thepresent disclosure. For example, the processor(s) 202 may processinformation within the memory(s) 204 to generate thirdinformation/signals and then transmit radio signals including the thirdinformation/signals through the transceiver(s) 206. The processor(s) 202may receive radio signals including fourth information/signals throughthe transceiver(s) 106 and then store information obtained by processingthe fourth information/signals in the memory(s) 204. The memory(s) 204may be connected to the processor(s) 202 and may store a variety ofinformation related to operations of the processor(s) 202. For example,the memory(s) 204 may store software code including commands forperforming a part or the entirety of processes controlled by theprocessor(s) 202 or for performing the descriptions, functions,procedures, suggestions, methods and/or operational flowcharts describedin the present disclosure. Herein, the processor(s) 202 and thememory(s) 204 may be a part of a communication modem/circuit/chipdesigned to implement RAT (e.g., LTE or NR). The transceiver(s) 206 maybe connected to the processor(s) 202 and transmit and/or receive radiosignals through one or more antennas 208. Each of the transceiver(s) 206may include a transmitter and/or a receiver. The transceiver(s) 206 maybe interchangeably used with RF unit(s). In the present disclosure, thesecond wireless device 200 may represent a communicationmodem/circuit/chip.

Hereinafter, hardware elements of the wireless devices 100 and 200 willbe described more specifically. One or more protocol layers may beimplemented by, without being limited to, one or more processors 102 and202. For example, the one or more processors 102 and 202 may implementone or more layers (e.g., functional layers such as physical (PHY)layer, media access control (MAC) layer, radio link control (RLC) layer,packet data convergence protocol (PDCP) layer, radio resource control(RRC) layer, and service data adaptation protocol (SDAP) layer). The oneor more processors 102 and 202 may generate one or more protocol dataunits (PDUs) and/or one or more service data unit (SDUs) according tothe descriptions, functions, procedures, suggestions, methods and/oroperational flowcharts disclosed in the present disclosure. The one ormore processors 102 and 202 may generate messages, control information,data, or information according to the descriptions, functions,procedures, suggestions, methods and/or operational flowcharts disclosedin the present disclosure. The one or more processors 102 and 202 maygenerate signals (e.g., baseband signals) including PDUs, SDUs,messages, control information, data, or information according to thedescriptions, functions, procedures, suggestions, methods and/oroperational flowcharts disclosed in the present disclosure and providethe generated signals to the one or more transceivers 106 and 206. Theone or more processors 102 and 202 may receive the signals (e.g.,baseband signals) from the one or more transceivers 106 and 206 andacquire the PDUs, SDUs, messages, control information, data, orinformation according to the descriptions, functions, procedures,suggestions, methods and/or operational flowcharts disclosed in thepresent disclosure.

The one or more processors 102 and 202 may be referred to ascontrollers, microcontrollers, microprocessors, or microcomputers. Theone or more processors 102 and 202 may be implemented by hardware,firmware, software, or a combination thereof. As an example, one or moreapplication specific integrated circuits (ASICs), one or more digitalsignal processors (DSPs), one or more digital signal processing devices(DSPDs), one or more programmable logic devices (PLDs), or one or morefield programmable gate arrays (FPGAs) may be included in the one ormore processors 102 and 202. Descriptions, functions, procedures,suggestions, methods and/or operational flowcharts disclosed in thepresent disclosure may be implemented using firmware or software and thefirmware or software may be configured to include the modules,procedures, or functions. Firmware or software configured to perform thedescriptions, functions, procedures, suggestions, methods and/oroperational flowcharts disclosed in the present disclosure may beincluded in the one or more processors 102 and 202 or stored in the oneor more memories 104 and 204 so as to be driven by the one or moreprocessors 102 and 202. The descriptions, functions, procedures,suggestions, methods and/or operational flowcharts disclosed in thepresent disclosure may be implemented using firmware or software in theform of code, commands, and/or a set of commands.

The one or more memories 104 and 204 may be connected to the one or moreprocessors 102 and 202 and store various types of data, signals,messages, information, programs, code, instructions, and/or commands.The one or more memories 104 and 204 may be configured by read-onlymemories (ROMs), random access memories (RAMs), electrically erasableprogrammable read-only memories (EPROMs), flash memories, hard drives,registers, cash memories, computer-readable storage media, and/orcombinations thereof. The one or more memories 104 and 204 may belocated at the interior and/or exterior of the one or more processors102 and 202. The one or more memories 104 and 204 may be connected tothe one or more processors 102 and 202 through various technologies suchas wired or wireless connection.

The one or more transceivers 106 and 206 may transmit user data, controlinformation, and/or radio signals/channels, mentioned in thedescriptions, functions, procedures, suggestions, methods and/oroperational flowcharts disclosed in the present disclosure, to one ormore other devices. The one or more transceivers 106 and 206 may receiveuser data, control information, and/or radio signals/channels, mentionedin the descriptions, functions, procedures, suggestions, methods and/oroperational flowcharts disclosed in the present disclosure, from one ormore other devices. For example, the one or more transceivers 106 and206 may be connected to the one or more processors 102 and 202 andtransmit and receive radio signals. For example, the one or moreprocessors 102 and 202 may perform control so that the one or moretransceivers 106 and 206 may transmit user data, control information, orradio signals to one or more other devices. The one or more processors102 and 202 may perform control so that the one or more transceivers 106and 206 may receive user data, control information, or radio signalsfrom one or more other devices.

The one or more transceivers 106 and 206 may be connected to the one ormore antennas 108 and 208 and the one or more transceivers 106 and 206may be configured to transmit and receive user data, controlinformation, and/or radio signals/channels, mentioned in thedescriptions, functions, procedures, suggestions, methods and/oroperational flowcharts disclosed in the present disclosure, through theone or more antennas 108 and 208. In the present disclosure, the one ormore antennas may be a plurality of physical antennas or a plurality oflogical antennas (e.g., antenna ports).

The one or more transceivers 106 and 206 may convert received radiosignals/channels, etc., from RF band signals into baseband signals inorder to process received user data, control information, radiosignals/channels, etc., using the one or more processors 102 and 202.The one or more transceivers 106 and 206 may convert the user data,control information, radio signals/channels, etc., processed using theone or more processors 102 and 202 from the base band signals into theRF band signals. To this end, the one or more transceivers 106 and 206may include (analog) oscillators and/or filters. For example, thetransceivers 106 and 206 can up-convert OFDM baseband signals to acarrier frequency by their (analog) oscillators and/or filters under thecontrol of the processors 102 and 202 and transmit the up-converted OFDMsignals at the carrier frequency. The transceivers 106 and 206 mayreceive OFDM signals at a carrier frequency and down-convert the OFDMsignals into OFDM baseband signals by their (analog) oscillators and/orfilters under the control of the transceivers 102 and 202.

In the implementations of the present disclosure, a UE may operate as atransmitting device in uplink (UL) and as a receiving device in downlink(DL). In the implementations of the present disclosure, a BS may operateas a receiving device in UL and as a transmitting device in DL.Hereinafter, for convenience of description, it is mainly assumed thatthe first wireless device 100 acts as the UE, and the second wirelessdevice 200 acts as the BS. For example, the processor(s) 102 connectedto, mounted on or launched in the first wireless device 100 may beconfigured to perform the UE behavior according to an implementation ofthe present disclosure or control the transceiver(s) 106 to perform theUE behavior according to an implementation of the present disclosure.The processor(s) 202 connected to, mounted on or launched in the secondwireless device 200 may be configured to perform the BS behavioraccording to an implementation of the present disclosure or control thetransceiver(s) 206 to perform the BS behavior according to animplementation of the present disclosure.

In the present disclosure, a BS is also referred to as a node B (NB), aneNode B (eNB), or a gNB.

FIG. 3 shows an example of a wireless device to which implementations ofthe present disclosure is applied.

The wireless device may be implemented in various forms according to ause-case/service (refer to FIG. 1 ).

Referring to FIG. 3 , wireless devices 100 and 200 may correspond to thewireless devices 100 and 200 of FIG. 2 and may be configured by variouselements, components, units/portions, and/or modules. For example, eachof the wireless devices 100 and 200 may include a communication unit110, a control unit 120, a memory unit 130, and additional components140. The communication unit 110 may include a communication circuit 112and transceiver(s) 114. For example, the communication circuit 112 mayinclude the one or more processors 102 and 202 of FIG. 2 and/or the oneor more memories 104 and 204 of FIG. 2 . For example, the transceiver(s)114 may include the one or more transceivers 106 and 206 of FIG.

2 and/or the one or more antennas 108 and 208 of FIG. 2 . The controlunit 120 is electrically connected to the communication unit 110, thememory 130, and the additional components 140 and controls overalloperation of each of the wireless devices 100 and 200. For example, thecontrol unit 120 may control an electric/mechanical operation of each ofthe wireless devices 100 and 200 based onprograms/code/commands/information stored in the memory unit 130.

The control unit 120 may transmit the information stored in the memoryunit 130 to the exterior (e.g., other communication devices) via thecommunication unit 110 through a wireless/wired interface or store, inthe memory unit 130, information received through the wireless/wiredinterface from the exterior (e.g., other communication devices) via thecommunication unit 110.

The additional components 140 may be variously configured according totypes of the wireless devices 100 and 200. For example, the additionalcomponents 140 may include at least one of a power unit/battery,input/output (I/O) unit (e.g., audio I/O port, video I/O port), adriving unit, and a computing unit. The wireless devices 100 and 200 maybe implemented in the form of, without being limited to, the robot (100a of FIG. 1 ), the vehicles (100 b-1 and 100 b-2 of FIG. 1 ), the XRdevice (100 c of FIG. 1 ), the hand-held device (100 d of FIG. 1 ), thehome appliance (100 e of FIG. 1 ), the IoT device (100 f of FIG. 1 ), adigital broadcast terminal, a hologram device, a public safety device,an MTC device, a medicine device, a FinTech device (or a financedevice), a security device, a climate/environment device, the AIserver/device (400 of FIG. 1 ), the BSs (200 of FIG. 1 ), a networknode, etc. The wireless devices 100 and 200 may be used in a mobile orfixed place according to a use-example/service.

In FIG. 3 , the entirety of the various elements, components,units/portions, and/or modules in the wireless devices 100 and 200 maybe connected to each other through a wired interface or at least a partthereof may be wirelessly connected through the communication unit 110.For example, in each of the wireless devices 100 and 200, the controlunit 120 and the communication unit 110 may be connected by wire and thecontrol unit 120 and first units (e.g., 130 and 140) may be wirelesslyconnected through the communication unit 110. Each element, component,unit/portion, and/or module within the wireless devices 100 and 200 mayfurther include one or more elements. For example, the control unit 120may be configured by a set of one or more processors. As an example, thecontrol unit 120 may be configured by a set of a communication controlprocessor, an application processor (AP), an electronic control unit(ECU), a graphical processing unit, and a memory control processor. Asanother example, the memory 130 may be configured by a RAM, a DRAM, aROM, a flash memory, a volatile memory, a non-volatile memory, and/or acombination thereof.

FIG. 4 shows another example of wireless devices to whichimplementations of the present disclosure is applied.

Referring to FIG. 4 , wireless devices 100 and 200 may correspond to thewireless devices 100 and 200 of FIG. 2 and may be configured by variouselements, components, units/portions, and/or modules.

The first wireless device 100 may include at least one transceiver, suchas a transceiver 106, and at least one processing chip, such as aprocessing chip 101. The processing chip 101 may include at least oneprocessor, such a processor 102, and at least one memory, such as amemory 104. The memory 104 may be operably connectable to the processor102. The memory 104 may store various types of information and/orinstructions. The memory 104 may store a software code 105 whichimplements instructions that, when executed by the processor 102,perform the descriptions, functions, procedures, suggestions, methodsand/or operational flowcharts disclosed in the present disclosure. Forexample, the software code 105 may implement instructions that, whenexecuted by the processor 102, perform the descriptions, functions,procedures, suggestions, methods and/or operational flowcharts disclosedin the present disclosure. For example, the software code 105 maycontrol the processor 102 to perform one or more protocols. For example,the software code 105 may control the processor 102 may perform one ormore layers of the radio interface protocol.

The second wireless device 200 may include at least one transceiver,such as a transceiver 206, and at least one processing chip, such as aprocessing chip 201. The processing chip 201 may include at least oneprocessor, such a processor 202, and at least one memory, such as amemory 204. The memory 204 may be operably connectable to the processor202. The memory 204 may store various types of information and/orinstructions. The memory 204 may store a software code 205 whichimplements instructions that, when executed by the processor 202,perform the descriptions, functions, procedures, suggestions, methodsand/or operational flowcharts disclosed in the present disclosure. Forexample, the software code 205 may implement instructions that, whenexecuted by the processor 202, perform the descriptions, functions,procedures, suggestions, methods and/or operational flowcharts disclosedin the present disclosure. For example, the software code 205 maycontrol the processor 202 to perform one or more protocols. For example,the software code 205 may control the processor 202 may perform one ormore layers of the radio interface protocol.

FIG. 5 shows an example of UE to which implementations of the presentdisclosure is applied.

Referring to FIG. 5 , a UE 100 may correspond to the first wirelessdevice 100 of FIG. 2 and/or the first wireless device 100 of FIG. 4 .

A UE 100 includes a processor 102, a memory 104, a transceiver 106, oneor more antennas 108, a power management module 110, a battery 1112, adisplay 114, a keypad 116, a subscriber identification module (SIM) card118, a speaker 120, and a microphone 122.

The processor 102 may be configured to implement the descriptions,functions, procedures, suggestions, methods and/or operationalflowcharts disclosed in the present disclosure. The processor 102 may beconfigured to control one or more other components of the UE 100 toimplement the descriptions, functions, procedures, suggestions, methodsand/or operational flowcharts disclosed in the present disclosure.Layers of the radio interface protocol may be implemented in theprocessor 102. The processor 102 may include ASIC, other chipset, logiccircuit and/or data processing device. The processor 102 may be anapplication processor. The processor 102 may include at least one of adigital signal processor (DSP), a central processing unit (CPU), agraphics processing unit (GPU), a modem (modulator and demodulator). Anexample of the processor 102 may be found in SNAPDRAGON™ series ofprocessors made by Qualcomm®, EXYNOS™ series of processors made bySamsung®, A series of processors made by Apple®, HELIO™ series ofprocessors made by MediaTek®, ATOM™ series of processors made by Intel®or a corresponding next generation processor.

The memory 104 is operatively coupled with the processor 102 and storesa variety of information to operate the processor 102. The memory 104may include ROM, RAM, flash memory, memory card, storage medium and/orother storage device. When the embodiments are implemented in software,the techniques described herein can be implemented with modules (e.g.,procedures, functions, etc.) that perform the descriptions, functions,procedures, suggestions, methods and/or operational flowcharts disclosedin the present disclosure. The modules can be stored in the memory 104and executed by the processor 102. The memory 104 can be implementedwithin the processor 102 or external to the processor 102 in which casethose can be communicatively coupled to the processor 102 via variousmeans as is known in the art.

The transceiver 106 is operatively coupled with the processor 102, andtransmits and/or receives a radio signal. The transceiver 106 includes atransmitter and a receiver. The transceiver 106 may include basebandcircuitry to process radio frequency signals. The transceiver 106controls the one or more antennas 108 to transmit and/or receive a radiosignal.

The power management module 110 manages power for the processor 102and/or the transceiver 106. The battery 112 supplies power to the powermanagement module 110.

The display 114 outputs results processed by the processor 102. Thekeypad 116 receives inputs to be used by the processor 102. The keypad16 may be shown on the display 114.

The SIM card 118 is an integrated circuit that is intended to securelystore the international mobile subscriber identity (IMSI) number and itsrelated key, which are used to identify and authenticate subscribers onmobile telephony devices (such as mobile phones and computers). It isalso possible to store contact information on many SIM cards.

The speaker 120 outputs sound-related results processed by the processor102. The microphone 122 receives sound-related inputs to be used by theprocessor 102.

FIGS. 6 and 7 show an example of protocol stacks in a 3GPP basedwireless communication system to which implementations of the presentdisclosure is applied.

In particular, FIG. 6 illustrates an example of a radio interface userplane protocol stack between a UE and a BS and FIG. 7 illustrates anexample of a radio interface control plane protocol stack between a UEand a BS. The control plane refers to a path through which controlmessages used to manage call by a UE and a network are transported. Theuser plane refers to a path through which data generated in anapplication layer, for example, voice data or Internet packet data aretransported. Referring to FIG. 6 , the user plane protocol stack may bedivided into Layer 1 (i.e., a PHY layer) and Layer 2. Referring to FIG.7 , the control plane protocol stack may be divided into Layer 1 (i.e.,a PHY layer), Layer 2, Layer 3 (e.g., an RRC layer), and a non-accessstratum (NAS) layer. Layer 1, Layer 2 and Layer 3 are referred to as anaccess stratum (AS).

In the 3GPP LTE system, the Layer 2 is split into the followingsublayers: MAC, RLC, and PDCP. In the 3GPP NR system, the Layer 2 issplit into the following sublayers: MAC, RLC, PDCP and SDAP. The PHYlayer offers to the MAC sublayer transport channels, the MAC sublayeroffers to the RLC sublayer logical channels, the RLC sublayer offers tothe PDCP sublayer RLC channels, the PDCP sublayer offers to the SDAPsublayer radio bearers. The SDAP sublayer offers to 5G core networkquality of service (QoS) flows.

In the 3GPP NR system, the main services and functions of the MACsublayer include: mapping between logical channels and transportchannels; multiplexing/de-multiplexing of MAC SDUs belonging to one ordifferent logical channels into/from transport blocks (TB) deliveredto/from the physical layer on transport channels; scheduling informationreporting; error correction through hybrid automatic repeat request(HARQ) (one HARQ entity per cell in case of carrier aggregation (CA));priority handling between UEs by means of dynamic scheduling; priorityhandling between logical channels of one UE by means of logical channelprioritization; padding. A single MAC entity may support multiplenumerologies, transmission timings and cells. Mapping restrictions inlogical channel prioritization control which numerology(ies), cell(s),and transmission timing(s) a logical channel can use.

Different kinds of data transfer services are offered by MAC. Toaccommodate different kinds of data transfer services, multiple types oflogical channels are defined, i.e., each supporting transfer of aparticular type of information. Each logical channel type is defined bywhat type of information is transferred. Logical channels are classifiedinto two groups: control channels and traffic channels. Control channelsare used for the transfer of control plane information only, and trafficchannels are used for the transfer of user plane information only.Broadcast control channel (BCCH) is a downlink logical channel forbroadcasting system control information, paging control channel (PCCH)is a downlink logical channel that transfers paging information, systeminformation change notifications and indications of ongoing publicwarning service (PWS) broadcasts, common control channel (CCCH) is alogical channel for transmitting control information between UEs andnetwork and used for UEs having no RRC connection with the network, anddedicated control channel (DCCH) is a point-to-point bi-directionallogical channel that transmits dedicated control information between aUE and the network and used by UEs having an RRC connection. Dedicatedtraffic channel (DTCH) is a point-to-point logical channel, dedicated toone UE, for the transfer of user information. A DTCH can exist in bothuplink and downlink. In downlink, the following connections betweenlogical channels and transport channels exist: BCCH can be mapped tobroadcast channel (BCH); BCCH can be mapped to downlink shared channel(DL-SCH); PCCH can be mapped to paging channel (PCH); CCCH can be mappedto DL-SCH; DCCH can be mapped to DL-SCH; and DTCH can be mapped toDL-SCH. In uplink, the following connections between logical channelsand transport channels exist: CCCH can be mapped to uplink sharedchannel (UL-SCH); DCCH can be mapped to UL-SCH; and DTCH can be mappedto UL-SCH.

The RLC sublayer supports three transmission modes: transparent mode(TM), unacknowledged mode (UM), and acknowledged node (AM). The RLCconfiguration is per logical channel with no dependency on numerologiesand/or transmission durations. In the 3GPP NR system, the main servicesand functions of the RLC sublayer depend on the transmission mode andinclude: transfer of upper layer PDUs; sequence numbering independent ofthe one in PDCP (UM and AM); error correction through ARQ (AM only);segmentation (AM and UM) and re-segmentation (AM only) of RLC SDUs;reassembly of SDU (AM and UM); duplicate detection (AM only); RLC SDUdiscard (AM and UM); RLC re-establishment; protocol error detection (AMonly).

In the 3GPP NR system, the main services and functions of the PDCPsublayer for the user plane include: sequence numbering; headercompression and decompression using robust header compression (ROHC);transfer of user data; reordering and duplicate detection; in-orderdelivery; PDCP PDU routing (in case of split bearers); retransmission ofPDCP SDUs; ciphering, deciphering and integrity protection; PDCP SDUdiscard; PDCP re-establishment and data recovery for RLC AM; PDCP statusreporting for RLC AM; duplication of PDCP PDUs and duplicate discardindication to lower layers. The main services and functions of the PDCPsublayer for the control plane include: sequence numbering; ciphering,deciphering and integrity protection; transfer of control plane data;reordering and duplicate detection; in-order delivery; duplication ofPDCP PDUs and duplicate discard indication to lower layers.

In the 3GPP NR system, the main services and functions of SDAP include:mapping between a QoS flow and a data radio bearer; marking QoS flow ID(QFI) in both DL and UL packets. A single protocol entity of SDAP isconfigured for each individual PDU session.

In the 3GPP NR system, the main services and functions of the RRCsublayer include: broadcast of system information related to AS and NAS;paging initiated by 5GC or NG-RAN; establishment, maintenance andrelease of an RRC connection between the UE and NG-RAN; securityfunctions including key management; establishment, configuration,maintenance and release of signaling radio bearers (SRBs) and data radiobearers (DRBs); mobility functions (including: handover and contexttransfer, UE cell selection and reselection and control of cellselection and reselection, inter-RAT mobility); QoS managementfunctions; UE measurement reporting and control of the reporting;detection of and recovery from radio link failure; NAS message transferto/from NAS from/to UE.

FIG. 8 shows a frame structure in a 3GPP based wireless communicationsystem to which implementations of the present disclosure is applied.

The frame structure shown in FIG. 8 is purely exemplary and the numberof subframes, the number of slots, and/or the number of symbols in aframe may be variously changed. In the 3GPP based wireless communicationsystem, OFDM numerologies (e.g., subcarrier spacing (SCS), transmissiontime interval (TTI) duration) may be differently configured between aplurality of cells aggregated for one UE. For example, if a UE isconfigured with different SCSs for cells aggregated for the cell, an(absolute time) duration of a time resource (e.g., a subframe, a slot,or a TTI) including the same number of symbols may be different amongthe aggregated cells. Herein, symbols may include OFDM symbols (orCP-OFDM symbols), SC-FDMA symbols (or discrete Fouriertransform-spread-OFDM (DFT-s-OFDM) symbols).

Referring to FIG. 8 , downlink and uplink transmissions are organizedinto frames. Each frame has T_(f)=10 ms duration. Each frame is dividedinto two half-frames, where each of the half-frames has 5 ms duration.Each half-frame consists of 5 subframes, where the duration T_(sf) persubframe is lms. Each subframe is divided into slots and the number ofslots in a subframe depends on a subcarrier spacing. Each slot includes14 or 12 OFDM symbols based on a cyclic prefix (CP). In a normal CP,each slot includes 14 OFDM symbols and, in an extended CP, each slotincludes 12 OFDM symbols. The numerology is based on exponentiallyscalable subcarrier spacing Δf=2*15 kHz.

Table 1 shows the number of OFDM symbols per slot N^(slot) _(symb), thenumber of slots per frame N^(frame,u) _(slot), and the number of slotsper subframe N^(subframe,u) _(slot) normal CP, according to thesubcarrier spacing Δf=2*15 kHz.

TABLE 1 u N^(slot) _(symb) N^(frame, u) _(slot) N^(subframe, u) _(slot)0 14 10 1 1 14 20 2 2 14 40 4 3 14 80 8 4 14 160 16

Table 2 shows the number of OFDM symbols per slot N^(slot) _(symb), thenumber of slots per frame N^(frame,u) _(slot), and the number of slotsper subframe N^(subframe,u) _(slot) or the extended CP, according to thesubcarrier spacing Δf=2^(u*)15 kHz.

TABLE 2 u N^(slot) _(symb) N^(frame, u) _(slot) N^(subframe, u) _(slot)2 12 40 4

A slot includes plural symbols (e.g., 14 or 12 symbols) in the timedomain. For each numerology (e.g., subcarrier spacing) and carrier, aresource grid of N^(size,u) _(grid,x)*N^(RB) _(sc) subcarriers andN^(subframe,u) _(slot) OFDM symbols is defined, starting at commonresource block (CRB) N^(start,u) _(grid) indicated by higher-layersignaling (e.g., RRC signaling), where N^(size,u) _(grid,x) is thenumber of resource blocks (RBs) in the resource grid and the subscript xis DL for downlink and UL for uplink. N^(RB) _(sc) is the number ofsubcarriers per RB. In the 3GPP based wireless communication system,N^(RB) _(sc) is 12 generally. There is one resource grid for a givenantenna port p, subcarrier spacing configuration u, and transmissiondirection (DL or UL). The carrier bandwidth N^(size,u) _(grid) forsubcarrier spacing configuration u is given by the higher-layerparameter (e.g., RRC parameter). Each element in the resource grid forthe antenna port p and the subcarrier spacing configuration u isreferred to as a resource element (RE) and one complex symbol may bemapped to each RE. Each RE in the resource grid is uniquely identifiedby an index kin the frequency domain and an index/representing a symbollocation relative to a reference point in the time domain. In the 3GPPbased wireless communication system, an RB is defined by 12 consecutivesubcarriers in the frequency domain.

In the 3GPP NR system, RBs are classified into CRBs and physicalresource blocks (PRBs). CRBs are numbered from 0 and upwards in thefrequency domain for subcarrier spacing configuration u. The center ofsubcarrier 0 of CRB 0 for subcarrier spacing configuration u coincideswith ‘point A’ which serves as a common reference point for resourceblock grids. In the 3GPP NR system, PRBs are defined within a bandwidthpart (BWP) and numbered from 0 to N^(size) _(BWP,i)−1 where i is thenumber of the bandwidth part. The relation between the physical resourceblock n_(PRB) in the bandwidth part i and the common resource blockn_(CRB) is as follows: n_(PRB)=n_(CRB)+N^(size) _(BWP,i), where N^(size)_(BWP,i) is the common resource block where bandwidth part startsrelative to CRB 0. The BWP includes a plurality of consecutive RBs. Acarrier may include a maximum of N (e.g., 5) BWPs. A UE may beconfigured with one or more BWPs on a given component carrier. Only oneBWP among BWPs configured to the UE can active at a time. The active BWPdefines the UE's operating bandwidth within the cell's operatingbandwidth.

The NR frequency band may be defined as two types of frequency range,i.e., FR1 and FR2. The numerical value of the frequency range may bechanged. For example, the frequency ranges of the two types (FR1 andFR2) may be as shown in Table 3 below. For ease of explanation, in thefrequency ranges used in the NR system, FR1 may mean “sub 6 GHz range”,FR2 may mean “above 6 GHz range,” and may be referred to as millimeterwave (mmW).

TABLE 3 Frequency Range Corresponding designation frequency rangeSubcarrier Spacing FR1  450 MHz-6000 MHz  15, 30, 60 kHz FR2 24250MHz-52600 MHz 60, 120, 240 kHz

As mentioned above, the numerical value of the frequency range of the NRsystem may be changed. For example, FR1 may include a frequency band of410 MHz to 7125 MHz as shown in Table 4 below. That is, FR1 may includea frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) or more. Forexample, a frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) ormore included in FR1 may include an unlicensed band. Unlicensed bandsmay be used for a variety of purposes, for example for communication forvehicles (e.g., autonomous driving).

TABLE 4 Frequency Range Corresponding designation frequency rangeSubcarrier Spacing FR1  410 MHz-7125 MHz  15, 30, 60 kHz FR2 24250MHz-52600 MHz 60, 120, 240 kHz

In the present disclosure, the term “cell” may refer to a geographicarea to which one or more nodes provide a communication system, or referto radio resources. A “cell” as a geographic area may be understood ascoverage within which a node can provide service using a carrier and a“cell” as radio resources (e.g., time-frequency resources) is associatedwith bandwidth which is a frequency range configured by the carrier. The“cell” associated with the radio resources is defined by a combinationof downlink resources and uplink resources, for example, a combinationof a DL component carrier (CC) and a UL CC. The cell may be configuredby downlink resources only, or may be configured by downlink resourcesand uplink resources. Since DL coverage, which is a range within whichthe node is capable of transmitting a valid signal, and UL coverage,which is a range within which the node is capable of receiving the validsignal from the UE, depends upon a carrier carrying the signal, thecoverage of the node may be associated with coverage of the “cell” ofradio resources used by the node. Accordingly, the term “cell” may beused to represent service coverage of the node sometimes, radioresources at other times, or a range that signals using the radioresources can reach with valid strength at other times.

In CA, two or more CCs are aggregated. A UE may simultaneously receiveor transmit on one or multiple CCs depending on its capabilities. CA issupported for both contiguous and non-contiguous CCs. When CA isconfigured, the UE only has one RRC connection with the network. At RRCconnection establishment/re-establishment/handover, one serving cellprovides the NAS mobility information, and at RRC connectionre-establishment/handover, one serving cell provides the security input.This cell is referred to as the primary cell (PCell). The PCell is acell, operating on the primary frequency, in which the UE eitherperforms the initial connection establishment procedure or initiates theconnection re-establishment procedure. Depending on UE capabilities,secondary cells (SCells) can be configured to form together with thePCell a set of serving cells. An SCell is a cell providing additionalradio resources on top of special cell (SpCell). The configured set ofserving cells for a UE therefore always consists of one PCell and one ormore SCells. For dual connectivity (DC) operation, the term SpCellrefers to the PCell of the master cell group (MCG) or the primary SCell

(PSCell) of the secondary cell group (SCG). An SpCell supports PUCCHtransmission and contention-based random access, and is alwaysactivated. The MCG is a group of serving cells associated with a masternode, comprised of the SpCell (PCell) and optionally one or more SCells.The SCG is the subset of serving cells associated with a secondary node,comprised of the PSCell and zero or more SCells, for a UE configuredwith DC. For a UE in RRC_CONNECTED not configured with CA/DC, there isonly one serving cell comprised of the PCell. For a UE in RRC_CONNECTEDconfigured with CA/DC, the term “serving cells” is used to denote theset of cells comprised of the SpCell(s) and all SCells. In DC, two MACentities are configured in a UE: one for the MCG and one for the SCG.

FIG. 9 shows a data flow example in the 3GPP NR system to whichimplementations of the present disclosure is applied.

Referring to FIG. 9 , “RB” denotes a radio bearer, and “H” denotes aheader. Radio bearers are categorized into two groups: DRBs for userplane data and SRBs for control plane data. The MAC PDU istransmitted/received using radio resources through the PHY layer to/froman external device. The MAC PDU arrives to the PHY layer in the form ofa transport block.

In the PHY layer, the uplink transport channels UL-SCH and RACH aremapped to their physical channels PUSCH and PRACH, respectively, and thedownlink transport channels DL-SCH, BCH and PCH are mapped to PDSCH,PBCH and PDSCH, respectively. In the PHY layer, uplink controlinformation (UCI) is mapped to PUCCH, and downlink control information(DCI) is mapped to PDCCH. A MAC PDU related to UL-SCH is transmitted bya UE via a PUSCH based on an UL grant, and a MAC PDU related to DL-SCHis transmitted by a BS via a PDSCH based on a DL assignment.

Hereinafter, Bandwidth part is described. Section 4.4.5 of 3GPP TS38.211 V15.7.0 may be referred.

A bandwidth part is a subset of contiguous common resource blocks for agiven numerology in bandwidth part on a given carrier.

A UE can be configured with up to four bandwidth parts in the downlinkwith a single downlink bandwidth part being active at a given time. TheUE is not expected to receive PDSCH, PDCCH, or CSI-RS (except for RRM)outside an active bandwidth part.

A UE can be configured with up to four bandwidth parts in the uplinkwith a single uplink bandwidth part being active at a given time. If aUE is configured with a supplementary uplink, the UE can in addition beconfigured with up to four bandwidth parts in the supplementary uplinkwith a single supplementary uplink bandwidth part being active at agiven time. The UE shall not transmit PUSCH or PUCCH outside an activebandwidth part. For an active cell, the UE shall not transmit SRSoutside an active bandwidth part.

FIG. 10 shows an example of bandwidth part (BWP) configurations to whichimplementations of the present disclosure is applied.

Referring to FIG. 10 , BWP consists of a group of contiguous physicalresource blocks (PRBs). The bandwidth (BW) of BWP cannot exceed theconfigured component carrier (CC) BW for the UE. The BW of the BWP mustbe at least as large as one synchronization signal (SS) block BW, butthe BWP may or may not contain SS block. Each BWP is associated with aspecific numerology, i.e., sub-carrier spacing (SCS) and cyclic prefix(CP) type. Therefore, the BWP is also a means to reconfigure a UE with acertain numerology.

As illustrated in the right figure of FIG. 10 , the network canconfigure multiple BWPs to a UE via radio resource control (RRC)signaling, which may overlap in frequency. The granularity of BWPconfiguration is one PRB. For each serving cell, DL and UL BWPs areconfigured separately and independently for paired spectrum and up tofour BWPs can be configured for DL and UL each. For unpaired spectrum, aDL BWP and a UL BWP are jointly configured as a pair and up to 4 pairscan be configured. There can be maximally 4 UL BWPs configured for asupplemental UL (SUL) as well.

FIG. 11 shows an example of contiguous BWPs and non-contiguous BWPs towhich implementations of the present disclosure is applied

Referring to FIG. 11 , for serving cell measurements, a UE may beconfigured with multiple BWPs contiguously or non-contiguously. In orderto derive quality of the serving cell, the UE measures only configuredBWPs, not all BWPs that belongs to the serving cell.

Each configured DL BWP includes at least one control resource set(CORESET) with UE-specific search space (USS). The USS is a searchingspace for UE to monitor possible reception of control informationdestined for the UE. In the primary carrier, at least one of theconfigured DL BWPs includes one CORESET with common search space (CSS).The CSS is a searching space for UE to monitor possible reception ofcontrol information common for all UEs or destined for the particularUE. If the CORESET of an active DL BWP is not configured with CSS, theUE is not required to monitor it. Note that UEs are expected to receiveand transmit only within the frequency range configured for the activeBWPs with the associated numerologies. However, there are exceptions. AUE may perform Radio Resource Management (RRM) measurement or transmitsounding reference signal (SRS) outside of its active BWP viameasurement gap.

FIG. 12 shows an example of multiple BWPs to which implementations ofthe present disclosure is applied.

Referring to FIG. 12 , 3 BWPs may be configured. The first BWP may span40 MHz band, and a subcarrier spacing of 15 kHz may be applied. Thesecond BWP may span 10 MHz band, and a subcarrier spacing of 15 kHz maybe applied. The third BWP may span 20 MHz band and a subcarrier spacingof 60 kHz may be applied. The UE may configure at least one BWP amongthe 3 BWPs as an active BWP, and may perform UL and/or DL datacommunication via the active BWP.

The BWP is also a tool to switch the operating numerology of a UE. Thenumerology of the DL BWP configuration is used at least for the PhysicalDownlink Control Channel (PDCCH), Physical Downlink Shared Channel(PDSCH) and corresponding demodulation RS (DMRS). Likewise, thenumerology of the UL BWP configuration is used at least for the PhysicalUplink Control Channel (PUCCH), Physical Uplink Shared Channel (PUSCH)and corresponding DMRS. On the other hand, it is noted that there is arestriction in the configuration of numerology at least in the earlyversion of NR. That is, the same numerology shall be used within thesame PUCCH group including both DL and UL.

Hereinafter, radio link failure related actions is described. Theoperations described below could be applied to implementations of thepresent disclosure. Section 5.3.11 of 3GPP TS 3GPP TS 38.331 V15.7.0 maybe referred.

Detection of physical layer problems in RRC_CONNECTED is described.

The UE shall:

1> upon receiving N310 consecutive “out-of-sync” indications for theSpCell from lower layers while neither T300, T301, T304, T311 nor T319are running:

2> start timer T310 for the corresponding SpCell.

Recovery of physical layer problems is described.

Upon receiving N311 consecutive “in-sync” indications for the SpCellfrom lower layers while T310 is running, the UE shall:

1> stop timer T310 for the corresponding SpCell.

In this case, the UE maintains the RRC connection without explicitsignalling, i.e. the

UE maintains the entire radio resource configuration.

Periods in time where neither “in-sync” nor “out-of-sync” is reported byL1 do not affect the evaluation of the number of consecutive “in-sync”or “out-of-sync” indications.

Detection of radio link failure is described.

The UE shall:

1> upon T310 expiry in PCell; or

1> upon random access problem indication from MCG MAC while neitherT300, T301, T304, T311 nor T319 are running; or

1> upon indication from MCG RLC that the maximum number ofretransmissions has been reached:

2> if the indication is from MCG RLC and CA duplication is configuredand activated, and for the corresponding logical channelallowedServingCells only includes SCell(s):

3> initiate the failure information procedure as specified in 5.7.5 toreport RLC failure.

2> else:

3> consider radio link failure to be detected for the MCG i.e. RLF;

3> if AS security has not been activated:

4> perform the actions upon going to RRC IDLE, with release cause‘other’;

3> else if AS security has been activated but SRB2 and at least one DRBhave not been setup:

4> perform the actions upon going to RRC IDLE, with release cause ‘RRCconnection failure’;

3> else:

4> initiate the connection re-establishment procedure.

The UE shall:

1> upon T310 expiry in PSCell; or

1> upon random access problem indication from SCG MAC; or

1> upon indication from SCG RLC that the maximum number ofretransmissions has been reached:

2> if the indication is from SCG RLC and CA duplication is configuredand activated; and for the corresponding logical channelallowedServingCells only includes SCell(s):

3> initiate the failure information procedure to report RLC failure.

2> else:

3> consider radio link failure to be detected for the SCG, i.e. SCG RLF;

3> initiate the SCG failure information procedure to report SCG radiolink failure.

Hereinafter, RRC connection re-establishment is described. Theoperations described below could be applied to implementations of thepresent disclosure. Section 5.3.7 of 3GPP TS 3GPP TS 38.331 V15.7.0 maybe referred.

The purpose of this procedure is to re-establish the RRC connection. AUE in RRC_CONNECTED, for which AS security has been activated with SRB2and at least one DRB setup, may initiate the procedure in order tocontinue the RRC connection. The connection re-establishment succeeds ifthe network is able to find and verify a valid UE context or, if the UEcontext cannot be retrieved, and the network responds with an RRCSetup.

The network applies the procedure as follows:

When AS security has been activated and the network retrieves orverifies the UE context:

to re-activate AS security without changing algorithms;

to re-establish and resume the SRB1;

When UE is re-establishing an RRC connection, and the network is notable to retrieve or verify the UE context:

to discard the stored AS Context and release all RBs;

to fallback to establish a new RRC connection.

If AS security has not been activated, the UE shall not initiate theprocedure but instead moves to RRC IDLE directly, with release cause‘other’. If AS security has been activated, but SRB2 and at least oneDRB are not setup, the UE does not initiate the procedure but insteadmoves to RRC IDLE directly, with release cause ‘RRC connection failure’.

The UE initiates the procedure when one of the following conditions ismet:

1> upon detecting radio link failure of the MCG; or

1> upon re-configuration with sync failure of the MCG; or

1> upon mobility from NR failure; or

1> upon integrity check failure indication from lower layers concerningSRB1 or SRB2, except if the integrity check failure is detected on theRRCReestablishment message; or

1> upon an RRC connection reconfiguration failure.

Upon initiation of the procedure, the UE shall:

1> stop timer T310, if running;

1> stop timer T304, if running;

1> start timer T311;

1> suspend all RBs, except SRBO;

1> reset MAC;

1> release the MCG SCell(s), if configured;

1> release spCellConfig, if configured;

1> if MR-DC is configured:

2> perform MR-DC release;

2> release p-NR-FR1, if configured;

2> release p-UE-FR1, if configured;

1> release delayBudgetReportingConfig, if configured, and stop timerT342, if running;

1> release overheatingAssistanceConfig, if configured, and stop timerT345, if running;

1> perform cell selection in accordance with the cell selection process.

The UE shall set the contents of RRCReestablishmentRequest message asfollows:

1> set the ue-Identity as follows:

2> set the c-RNTI to the C-RNTI used in the source PCell(reconfiguration with sync or mobility from NR failure) or used in thePCell in which the trigger for the re-establishment occurred (othercases);

2> set the physCellld to the physical cell identity of the source PCell(reconfiguration with sync or mobility from NR failure) or of the PCellin which the trigger for the re-establishment occurred (other cases);

2> set the shortMAC-I to the 16 least significant bits of the MAC-Icalculated:

3> over the ASN.1 encoded as per clause 8 (i.e., a multiple of 8 bits)VarShortMAC-Input;

3> with the KRRont key and integrity protection algorithm that was usedin the source PCell (reconfiguration with sync or mobility from NRfailure) or of the PCell in which the trigger for the re-establishmentoccurred (other cases); and

3> with all input bits for COUNT, BEARER and DIRECTION set to binaryones;

1> set the reestablishmentCause as follows:

2> if the re-establishment procedure was initiated due toreconfiguration failure:

3> set the reestablishmentCause to the value reconfigurationFailure;

2> else if the re-establishment procedure was initiated due toreconfiguration with sync failure:

3> set the reestablishmentCause to the value handoverFailure;

2> else:

3> set the reestablishmentCause to the value otherFailure;

1> re-establish PDCP for SRB1;

1> re-establish RLC for SRB1;

1> apply the specified configuration for SRB1;

1> configure lower layers to suspend integrity protection and cipheringfor SRB1;

Ciphering is not applied for the subsequent RRCReestablishment messageused to resume the connection. An integrity check is performed by lowerlayers, but merely upon request from RRC.

1> resume SRB1;

1> submit the RRCReestablishmentRequest message to lower layers fortransmission.

Reception of the RRCReestablishment by the UE is described.

The UE shall:

1> stop timer T301;

1> consider the current cell to be the PCell;

1> store the nextHopChainingCount value indicated in theRRCReestablishment message;

1> update the K_(gNB) key based on the current K_(gNB) key or the NH,using the stored nextHopChainingCount value;

1> derive the KRRcenc and KUPenc keys associated with the previouslyconfigured cipheringAlgorithm;

1> derive the KRRcint and Kupint keys associated with the previouslyconfigured integrityProtAlgorithm.

1> request lower layers to verify the integrity protection of the

RRCReestablishment message, using the previously configured algorithmand the KRRCint key;

1> if the integrity protection check of the RRCReestablishment messagefails:

2> perform the actions upon going to RRC IDLE, with release cause ‘RRCconnection failure’, upon which the procedure ends;

1> configure lower layers to resume integrity protection for SRB1 usingthe previously configured algorithm and the KRRcint key immediately,i.e., integrity protection shall be applied to all subsequent messagesreceived and sent by the UE, including the message used to indicate thesuccessful completion of the procedure;

1> configure lower layers to resume ciphering for SRB1 using thepreviously configured algorithm and, the KRRcenc key immediately, i.e.,ciphering shall be applied to all subsequent messages received and sentby the UE, including the message used to indicate the successfulcompletion of the procedure;

1> release the measurement gap configuration indicated by themeasGapConfig, if configured;

1> submit the RRCReestablishmentComplete message to lower layers fortransmission;

1> the procedure ends.

Hereinafter, SCG failure information is described. The operationsdescribed below could be applied to implementations of the presentdisclosure. Section 5.7.3 of 3GPP TS 38.331 V15.7.0 may be referred.

The purpose of this procedure is to inform E-UTRAN or NR MN about an SCGfailure the UE has experienced i.e. SCG radio link failure, failure ofSCG reconfiguration with sync, SCG configuration failure for RRC messageon SRB3 and SCG integrity check failure.

A UE initiates the procedure to report SCG failures when SCGtransmission is not suspended and when one of the following conditionsis met:

1> upon detecting radio link failure for the SCG;

1> upon reconfiguration with sync failure of the SCG;

1> upon SCG configuration failure;

1> upon integrity check failure indication from SCG lower layersconcerning SRB3.

Upon initiating the procedure, the UE shall:

1> suspend SCG transmission for all SRBs and DRBs;

1> reset SCG MAC;

1> stop T304, if running;

1> if the UE is in (NG)EN-DC:

2> initiate transmission of the SCGFailurelnformationNR message

1> else:

2> initiate transmission of the SCGFailurelnformation message

Failure type determination for (NG)EN-DC is described.

The UE shall set the SCG failure type as follows:

1> if the UE initiates transmission of the SCGFailurelnformationNRmessage due to T310 expiry:

2> set the failureType as t310-Expiry;

1> else if the UE initiates transmission of the SCGFailurelnformationNRmessage to provide reconfiguration with sync failure information for anSCG:

2> set the failureType as synchReconfigFailure-SCG;

1> else if the UE initiates transmission of the SCGFailurelnformationNRmessage to provide random access problem indication from SCG MAC:

2> set the failureType as randomAccessProblem;

1> else if the UE initiates transmission of the SCGFailurelnformationNRmessage to provide indication from SCG RLC that the maximum number ofretransmissions has been reached:

2> set the failureType as rlc-MaxNumRetx;

1> else if the UE initiates transmission of the SCGFailurelnformationNRmessage due to SRB3 integrity check failure:

2> set the failureType as srb3-IntegrityFailure;

1> else if the UE initiates transmission of the SCGFailurelnformationNRmessage due to Reconfiguration failure of NR RRC reconfigurationmessage:

2> set the failureType as scg-reconfigFailure.

The UE shall set the contents of the MeasResultSCG-Failureas follows:

1> for each MeasObjectNR configured on NR SCG for which a measld isconfigured and measurement results are available:

2> include an entry in measResultPerMOList;

2> if there is a measld configured with the MeasObjectNR and areportConfig which has rsType set to ssb:

3> set ssbFrequency to the value indicated by ssbFrequency as includedin the MeasObjectNR;

2> if there is a measld configured with the MeasObjectNR and areportConfig which has rsType set to csi-rs:

3> set refFreqCSI-RS to the value indicated by refFreqCSI-RS as includedin the associated measurement object;

2> if a serving cell is associated with the MeasObjectNR:

3> set measResultServingCell to include the available quantities of theconcerned cell and in accordance with the performance requirements;

2> set the measResultNeighCellList to include the best measured cells,ordered such that the best cell is listed first, and based onmeasurements collected up to the moment the UE detected the failure, andset its fields as follows;

3> ordering the cells with sorting as follows:

4> based on SS/PBCH block if SS/PBCH block measurement results areavailable and otherwise based on CSI-RS;

4> using RSRP if RSRP measurement results are available, otherwise usingRSRQ if RSRQ measurement results are available, otherwise using SINR;

3> for each neighbour cell included:

4> include the optional fields that are available.

The measured quantities are filtered by the L3 filter as configured inthe mobility measurement configuration. The measurements are based onthe time domain measurement resource restriction, if configured.Blacklisted cells are not required to be reported.

The UE shall set the contents of the SCGFailurelnformation message asfollows:

1> if the UE initiates transmission of the SCGFailurelnformation messagedue to T310 expiry:

2> set the failureType as t310-Expiry;

1> else if the UE initiates transmission of the SCGFailurelnformationmessage to provide reconfiguration with sync failure information for anSCG:

2> set the failureType as synchReconfigFailure-SCG;

1> else if the UE initiates transmission of the SCGFailurelnformationmessage to provide random access problem indication from SCG MAC:

2> set the failureType as randomAccessProblem;

1> else if the UE initiates transmission of the SCGFailurelnformationmessage to provide indication from SCG RLC that the maximum number ofretransmissions has been reached:

2> set the failureType as rlc-MaxNumRetx;

1> else if the UE initiates transmission of the SCGFailurelnformationmessage due to SRB3 IP check failure:

2> set the failureType as srb3-IntegrityFailure;

1> else if the UE initiates transmission of the SCGFailurelnformationmessage due to Reconfiguration failure of NR RRC reconfigurationmessage:

2> set the failureType as scg-reconfigFailure.

1> include and set MeasResultSCG-F ailure;

1> for each NR frequency the UE is configured to measure by a MeasConfigassociate with the MCG and for which measurement results are available:

2> set the measResultFreqList to include the best measured cells,ordered such that the best cell is listed first using RSRP to order ifRSRP measurement results are available for cells on this frequency,otherwise using RSRQ to order if RSRQ measurement results are availablefor cells on this frequency, otherwise using SINR to order, and based onmeasurements collected up to the moment the UE detected the failure, andfor each cell that is included, include the optional fields that areavailable;

Field measResultSCG-Failure is used to report available results for NRfrequencies the UE is configured to measure by SCG RRC signalling.

The UE shall submit the SCGFailurelnformation message to lower layersfor transmission.

Hereinafter, Cell Reservations and Access Restrictions are described.The operations described below could be applied to implementations ofthe present disclosure. Section 5.3 of 3GPP TS 38.304 V15.5.0 may bereferred.

There are two mechanisms which allow an operator to impose cellreservations or access restrictions. The first mechanism uses indicationof cell status and special reservations for control of cell selectionand reselection procedures. The second mechanism, referred to as UnifiedAccess Control, shall allow preventing selected access categories oraccess identities from sending initial access messages for load controlreasons.

Cell status and cell reservations are described.

Cell status and cell reservations are indicated in the MIB or SIB1message by means of three fields:

cellBarred (IE type: “barred” or “not barred”)

Indicated in MIB message. In case of multiple PLMNs indicated in SIB1,this field is common for all PLMNs

cellReservedForOperatorUse (IE type: “reserved” or “not reserved”)

Indicated in SIB1 message. In case of multiple PLMNs indicated in SIB1,this field is specified per PLMN.

cellReservedForOtherUse (IE type: “true”)

Indicated in SIB1 message. In case of multiple PLMNs indicated in SIB1,this field is common for all PLMNs.

When cell status is indicated as “not barred” and “not reserved” foroperator use and not “true” for other use,

All UEs shall treat this cell as candidate during the cell selection andcell reselection procedures.

When cell status is indicated as “true” for other use,

The UE shall treat this cell as if cell status is “barred”.

When cell status is indicated as “not barred” and “reserved” foroperator use for any

PLMN and not “true” for other use,

UEs assigned to Access Identity 11 or 15 operating in their HPLMN/EHPLMNshall treat this cell as candidate during the cell selection andreselection procedures if the field cellReservedForOperatorUse for thatPLMN set to “reserved”.

UEs assigned to an Access Identity 0, 1, 2 and 12 to 14 shall behave asif the cell status is “barred” in case the cell is “reserved foroperator use” for the registered PLMN or the selected PLMN.

Access Identities 11, 15 are only valid for use in the HPLMN/EHPLMN;Access Identities 12, 13, 14 are only valid for use in the home country.

When cell status “barred” is indicated or to be treated as if the cellstatus is “barred”,

The UE is not permitted to select/reselect this cell, not even foremergency calls.

The UE shall select another cell according to the following rule:

If the cell is to be treated as if the cell status is “barred” due tobeing unable to acquire the MIB:

the UE may exclude the barred cell as a candidate for cellselection/reselection for up to 300 seconds.

the UE may select another cell on the same frequency if the selectioncriteria are fulfilled.

else:

If the cell is to be treated as if the cell status is “barred” due tobeing unable to acquire the SIB1 or due to trackingAreaCode being absentin SIB1:

The UE may exclude the barred cell as a candidate for cellselection/reselection for up to 300 seconds.

If the field intraFreqReselection in MIB message is set to “allowed”,the UE may select another cell on the same frequency if re-selectioncriteria are fulfilled;

The UE shall exclude the barred cell as a candidate for cellselection/reselection for 300 seconds.

If the field intraFreqReselection in MIB message is set to “not allowed”the UE shall not re-select a cell on the same frequency as the barredcell;

The UE shall exclude the barred cell and the cells on the same frequencyas a candidate for cell selection/reselection for 300 seconds.

The cell selection of another cell may also include a change of RAT.

Meanwhile, if a single bandwidth part (BWP) is activated, a wirelessdevice may declare the radio link failure (RLF) and initiate therecovery procedure (for example, RRC re-establishment), when thewireless device detects the radio link problem for the activated BWP.

When multiple BWPs are activated, a wireless device may need to performthe radio link monitoring (RLM) for each activated BWP.

If a wireless device declares the RLF when the radio link problem isdetected from an activated BWP even though there is another availableactivated BWP, the wireless device would undergo unnecessary serviceinterruption due to the recovery procedure whenever the radio linkproblem happens within a single BWP.

Therefore, studies for declaring radio link failure in multiple activebandwidth parts in a wireless communication system are required.

Hereinafter, a method for declaring radio link failure in multipleactive bandwidth parts in a wireless communication system, according tosome embodiments of the present disclosure, will be described withreference to the following drawings.

The following drawings are created to explain specific embodiments ofthe present disclosure. The names of the specific devices or the namesof the specific signals/messages/fields shown in the drawings areprovided by way of example, and thus the technical features of thepresent disclosure are not limited to the specific names used in thefollowing drawings. Herein, a wireless device may be referred to as auser equipment (UE).

FIG. 13 shows an example of a method for declaring radio link failure inmultiple active bandwidth parts in a wireless communication system,according to some embodiments of the present disclosure.

In particular, FIG. 13 shows an example of a method performed by awireless device.

In step S1301, a wireless device may activate a first BWP and a secondBWP for a serving cell.

For example, a wireless device may include multiple BWPs (for example,four BWPs). A wireless device may activate plurality of the BWPs. Inother words, a wireless device may use the plurality of the activatedBWPs for wireless communication.

In step S1302, a wireless device may perform a radio link monitoring(RLM) on the first BWP and the second BWP.

For example, a wireless device may perform a RLM on all of the activatedBWPs.

For other example, a wireless device may perform a RLM on all of theBWPs. In other words, a wireless device may perform the RLM on all ofthe activated BWPs and all of the deactivated BWPs.

In step S1303, a wireless device may detect a radio link problem on thefirst BWP.

For example, a wireless device may perform a transmission to inform thenetwork of the radio link problem on the first BWP. For example, awireless device may perform the transmission, to inform the network ofthe radio link problem on the first BWP, on the second BWP.

According to some embodiments of the present disclosure, the radio linkproblem on the first BWP may be detected upon detecting that measurementresult of the first BWP is lower than a threshold. For example, thethreshold may be configured by a network and/or by the wireless device.

According to some embodiments of the present disclosure, the radio linkproblem on the first BWP may be detected upon receiving, by an upperlayer of the wireless device, consecutive “out-of-sync (OOS)”indications from a physical layer of the wireless device. For example,the upper layer may be a Radio Resource Control (RRC) layer.

According to some embodiments of the present disclosure, a wirelessdevice may start a radio link problem timer (for example, T310) upondetecting a physical layer problem on the first BWP. For example, thephysical layer problem may be detected upon receiving, by an upper layerof the wireless device, consecutive “out-of-sync (OOS)” indications froma physical layer of the wireless device. In this case, the radio linkproblem on the first BWP may be detected upon detecting expiry of theradio link problem timer.

For example, the radio link problem timer may be configured per activeBWPs. For example, the radio link problem timer may be configured foreach of the first BWP and the second BWP, respectively. For example, theradio link problem timer may be configured for each of the BWPs.

According to some embodiments of the present disclosure, a wirelessdevice may stop the radio link problem timer based on that a recovery ofphysical layer problems is detected.

For example, a wireless device may stop the radio link problem timerupon receiving consecutive “in-sync (IS)” indications.

In step S1304, a wireless device may decide whether to declare a radiolink failure (RLF) for the serving cell based on radio link state ofboth the first BWP and the second BWP.

According to some embodiments of the present disclosure, a wirelessdevice may decide not to declare the RLF for the serving cell based onthat the second BWP is activated.

According to some embodiment of the present disclosure, a wirelessdevice may deactivate the first BWP upon detecting the radio linkproblem on the first BWP, in step S1303.

For example, a wireless device may detect a radio link problem on thesecond BWP. Upon detecting the radio link problem on the second BWP, awireless device may decide whether to declare the RLF for the servingcell based on radio link state of the second BWP.

For example, a wireless device may decide whether to declare the RLF forthe serving cell based on radio link state of all of the activated BWP.In this case, only the second BWP may be activated. Since the radio linkproblem is detected on the second BWP, a wireless device may declare theRLF for the serving cell.

For example, a wireless device may initiate a recovery procedure upondeclaring the RLF for the serving cell. For example, a wireless devicemay perform RRC re-establishment procedure, transition to RRC IDLE,and/or PCell/PSCell failure indication.

According to some embodiment of the present disclosure, a wirelessdevice may decide whether to declare the RLF for the serving cell basedon the radio link state of all of the activated BWPs. For example, awireless device may declare the RLF for the serving cell, when radiolink problems are detected on all of the activated BWPs.

According to some embodiments of the present disclosure, the wirelessdevice may be in communication with at least one of a user equipment, anetwork, or an autonomous vehicle other than the wireless device.

FIG. 14 shows an example of a method for declaring radio link failure inmultiple active bandwidth parts performed by a User Equipment (UE) in awireless communication system, according to some embodiments of thepresent disclosure.

According to some embodiments of the present disclosure, UE may decidewhether to declare the radio link failure for a serving cell based onthe radio link state of other active bandwidth parts that belong to theserving cell, when the radio link problem is detected from an activebandwidth part that belongs to the serving cell.

That is, the radio link failure for the serving cell may be determinedbased on not only the radio link problem from an active bandwidth partbelonging to the serving cell but also radio link state from otheractive bandwidth parts belonging to the serving cell.

In this case, it may be assumed that radio link monitoring is performedper active bandwidth part among multiple active bandwidth part. It maybe further assumed that the radio link problem timer (for example, T310)is running per active bandwidth part.

In step S1401, UE may monitor the radio link, for example, perform RadioLink Monitoring, for multiple active bandwidth parts.

For example, UE may perform the RLM for all or part of serving cells.For each serving cell there may be more than one active bandwidth part.UE may perform the RLM per active bandwidth part.

In step S1402, UE may detect the radio link problem at an activebandwidth part that belongs to a serving cell.

For example, UE may consider the radio link problem is detected at anactive bandwidth part when the measurement result of the activebandwidth part is lower than a threshold.

For example, UE may consider the radio link problem is detected at anactive bandwidth part when the physical layer problem is detected fromthe active bandwidth part based on the measurement result, for example,upon receiving N-consecutive “out-of-sync” indications from physicallayer for the active bandwidth part, or upon expiry of radio linkproblem timer (for example, T310) for the active bandwidth part. Forexample, UE may start the radio link problem timer for an activebandwidth part upon receiving N-consecutive “out-of-sync” indicationsfrom physical layer for the active bandwidth part.

According to some embodiment of the present disclosure, the radio linkproblem timer (for example, T310) may be per bandwidth part. In thiscase, UE may start the radio link problem timer when the physical layerproblem is detected for an active BWP. When the radio link problem timerexpires for all active BWPs that belong to a serving cell, UE maydeclare the RLF for the serving cell or cell group that the serving cellbelongs to.

According to some embodiment of the present disclosure, the radio linkproblem timer (for example, T310) may be configured per cell. In thiscase, UE may start the radio link problem timer when the physical layerproblem is detected for all active BWPs that belong to a serving cell.Upon expiry of the radio link problem timer, UE may declare the RLF forthe serving cell or cell group that the serving cell belongs to.

In step S1403, UE may decide whether to declare the radio link failurefor the serving cell based on the radio link state of other activebandwidth parts that belong to the serving cell.

When the radio link problem is detected from an active bandwidth partthat belongs to a serving cell, if the radio link problem is detectedfrom all active bandwidth parts that belong to the serving cell, UE maydeclare the radio link failure for the serving cell or correspondingserving cell group, and initiate the recovery procedure, for example,RRC re-establishment or MCG and/or SCG failure information procedure.

For example, UE may inform network that the radio link problem isdetected from the active bandwidth. For example, UE may deactivate theactive bandwidth part from which the radio link problem is detected.

After informing network of the radio link problem for active BWP, thenew active BWP may be configured for the UE by network.

FIG. 15 shows an example of declaring radio link failure in multipleactive bandwidth parts performed by a UE, according to some embodimentsof the present disclosure.

Referring to FIG. 15 , there are two active BWPs for a serving cell. Theradio link monitoring may be performed per active BWP. The radio linkproblem timer, for example, T310, may be running per active BWP.

First, N310 consecutive number of “out-of-sync” indications may bereceived from physical layer for the first active bandwidth part, uponwhich the radio link problem timer (for example, T310) for the firstbandwidth part stars to running. Additionally, N310 consecutive numberof “out-of-sync” indications may be also received from physical layerfor the second active bandwidth part, upon which the radio link problemtimer (for example, T310) for the second bandwidth part stars torunning.

Upon expiry of the radio link problem timer (for example, T310) for thefirst bandwidth part, UE may consider radio link problem from the firstactive bandwidth part. UE may check radio link status of the otheractive bandwidth parts belonging to the serving cell.

Since the radio link problem timer, (for example, T310) for the secondbandwidth part is still running, which means the radio link problem isnot yet detected from the second active bandwidth part, UE may notdeclare radio link failure for the serving cell.

UE may deactivate and/or release the first active bandwidth part. UE maytransmit to the network information for the first active bandwidth partfrom which the radio link problem is detected.

Upon expiry of the radio link problem timer (for example, T310) for thesecond bandwidth part, UE may consider radio link problem from thesecond active bandwidth part.

UE may check radio link status of the other active bandwidth partsbelonging to the serving cell. Since there is no available activebandwidth part belonging to the serving cell, UE may declare radio linkfailure for the serving cell, and initiate a recovery procedure for theserving cell, for example, RRC re-establishment procedure, transition toRRC IDLE, and/or PCell/PSCell failure indication.

According to some embodiments of the present disclosure, for PCell, fourbandwidth parts (for example, BWP 1, 2, 3 and 4) are configured, andamong them three bandwidth parts could be activated (for example, BWP1,2 and 4).

For example, UE may detect the radio link problem from BWP1 of PCell. UEmay check whether other active BWPs (for example, BWP2 and 4) areavailable or not, and find that BWP2 is still available, for example,the radio link problem has been detected for BWP1 and 4.

In this cast, the UE may not declare the radio link failure for PCell,and inform the network that the BWP1 and 4 are unavailable. For example,UE may autonomously deactivate the BWP1 and 4.

For example, when UE detects the radio link problem for BWP 2, and findsthat there is no available active BWP for PCell anymore, the UE maydeclare the RLF for PCell, and initiate RRC re-establishment procedure.

Hereinafter, an apparatus for declaring radio link failure in multipleactive bandwidth parts in a wireless communication system, according tosome embodiments of the present disclosure, will be described. Herein,the apparatus may be a wireless device (100 or 200) in FIGS. 2, 3, and 5.

For example, a wireless device may perform methods described in FIGS. 13to 15 . The detailed description overlapping with the above-describedcontents could be simplified or omitted.

Referring to FIG. 5 , a wireless device 100 may include a processor 102,a memory 104, and a transceiver 106.

According to some embodiments of the present disclosure, the processor102 may be configured to be coupled operably with the memory 104 and thetransceiver 106.

The processor 102 may be configured to activate a first bandwidth part(BWP) and a second BWP for a serving cell. The processor 102 may beconfigured to perform a radio link monitoring (RLM) on the first BWP andthe second BWP. The processor 102 may be configured to detect a radiolink problem on the first BWP. The processor 102 may be configured todecide whether to declare a radio link failure (RLF) for the servingcell based on radio link state of both the first BWP and the second BWP.

For example, the processor 102 may be configured to decide not todeclare the RLF for the serving cell based on that the second BWP isactivated.

For example, the processor 102 may be configured to deactivate the firstBWP upon detecting the radio link problem on the first BWP.

According to some embodiment of the present disclosure, the processor102 may be configured to detect a radio link problem on the second BWP.The processor 102 may be configured to decide whether to declare the RLFfor the serving cell based on radio link state of the second BWP. Theprocessor 102 may be configured to declare the RLF for the serving cell.

For example, the processor 102 may be configured to initiate a recoveryprocedure upon declaring the RLF for the serving cell.

For example, the RLF for the serving cell may be decided based on radiostate of all of activated BWPs for the serving cell.

According to some embodiments of the present disclosure, the processor102 may be configured to control the transceiver 106 to perform atransmission to inform the network of the radio link problem on thefirst BWP. For example, the transmission may be performed on the secondBWP.

According to some embodiments of the present disclosure, the radio linkproblem on the first BWP may be detected upon detecting that measurementresult of the first BWP is lower than a threshold.

According to some embodiments of the present disclosure, the radio linkproblem on the first BWP may be detected upon receiving, by an upperlayer of the wireless device, consecutive “out-of-sync” indications froma physical layer of the wireless device.

According to some embodiments of the present disclosure, the processor102 may be configured to start a radio link problem timer upon detectinga physical layer problem on the first BWP.

In this case, the radio link problem on the first BWP may be detectedupon detecting expiry of the radio link problem timer.

For example, the radio link problem timer may be configured for each ofthe first BWP and the second BWP, respectively.

According to some embodiments of the present disclosure, the processor102 may be configured to be in communication with at least one of a userequipment, a network, or an autonomous vehicle other than the wirelessdevice.

Hereinafter, a processor for a wireless device for declaring radio linkfailure in multiple active bandwidth parts in a wireless communicationsystem, according to some embodiments of the present disclosure, will bedescribed.

The processor may be configured to control the wireless device toactivate a first bandwidth part (BWP) and a second BWP for a servingcell. The processor may be configured to control the wireless device toperform a radio link monitoring (RLM) on the first BWP and the secondBWP. The processor may be configured to control the wireless device todetect a radio link problem on the first BWP. The processor may beconfigured to control the wireless device to decide whether to declare aradio link failure (RLF) for the serving cell based on radio link stateof both the first BWP and the second BWP.

For example, the processor may be configured to control the wirelessdevice to decide not to declare the RLF for the serving cell based onthat the second BWP is activated.

For example, the processor may be configured to control the wirelessdevice to deactivate the first BWP upon detecting the radio link problemon the first BWP.

According to some embodiment of the present disclosure, the processormay be configured to control the wireless device to detect a radio linkproblem on the second BWP. The processor may be configured to controlthe wireless device to decide whether to declare the RLF for the servingcell based on radio link state of the second BWP. The processor may beconfigured to control the wireless device to declare the RLF for theserving cell.

For example, the processor may be configured to control the wirelessdevice to initiate a recovery procedure upon declaring the RLF for theserving cell.

For example, the RLF for the serving cell may be decided based on radiostate of all of activated BWPs for the serving cell.

According to some embodiments of the present disclosure, the processormay be configured to control the wireless device to perform atransmission to inform the network of the radio link problem on thefirst BWP. For example, the transmission may be performed on the secondBWP.

According to some embodiments of the present disclosure, the radio linkproblem on the first BWP may be detected upon detecting that measurementresult of the first BWP is lower than a threshold.

According to some embodiments of the present disclosure, the radio linkproblem on the first BWP may be detected upon receiving, by an upperlayer of the wireless device, consecutive “out-of-sync” indications froma physical layer of the wireless device.

According to some embodiments of the present disclosure, the processormay be configured to control the wireless device to start a radio linkproblem timer upon detecting a physical layer problem on the first BWP.

In this case, the radio link problem on the first BWP may be detectedupon detecting expiry of the radio link problem timer.

For example, the radio link problem timer may be configured for each ofthe first BWP and the second BWP, respectively.

According to some embodiments of the present disclosure, the processormay be configured to control the wireless device to be in communicationwith at least one of a user equipment, a network, or an autonomousvehicle other than the wireless device.

Hereinafter, a non-transitory computer-readable medium has storedthereon a plurality of instructions for declaring radio link failure inmultiple active bandwidth parts in a wireless communication system,according to some embodiments of the present disclosure, will bedescribed.

According to some embodiment of the present disclosure, the technicalfeatures of the present disclosure could be embodied directly inhardware, in a software executed by a processor, or in a combination ofthe two. For example, a method performed by a wireless device in awireless communication may be implemented in hardware, software,firmware, or any combination thereof. For example, a software may residein RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory,registers, hard disk, a removable disk, a CD-ROM, or any other storagemedium.

Some example of storage medium is coupled to the processor such that theprocessor can read information from the storage medium. In thealternative, the storage medium may be integral to the processor. Theprocessor and the storage medium may reside in an ASIC. For otherexample, the processor and the storage medium may reside as discretecomponents.

The computer-readable medium may include a tangible and non-transitorycomputer-readable storage medium.

For example, non-transitory computer-readable media may include randomaccess memory (RAM) such as synchronous dynamic random access memory(SDRAM), read-only memory (ROM), non-volatile random access memory(NVRAM), electrically erasable programmable read-only memory (EEPROM),FLASH memory, magnetic or optical data storage media, or any othermedium that can be used to store instructions or data structures.Non-transitory computer-readable media may also include combinations ofthe above.

In addition, the method described herein may be realized at least inpart by a computer-readable communication medium that carries orcommunicates code in the form of instructions or data structures andthat can be accessed, read, and/or executed by a computer.

According to some embodiment of the present disclosure, a non-transitorycomputer-readable medium has stored thereon a plurality of instructions.The stored a plurality of instructions may be executed by a processor ofa wireless device.

The stored a plurality of instructions may cause the wireless device toactivate a first bandwidth part (BWP) and a second BWP for a servingcell. The stored a plurality of instructions may cause the wirelessdevice to perform a radio link monitoring (RLM) on the first BWP and thesecond BWP. The stored a plurality of instructions may cause thewireless device to detect a radio link problem on the first BWP. Thestored a plurality of instructions may cause the wireless device todecide whether to declare a radio link failure (RLF) for the servingcell based on radio link state of both the first BWP and the second BWP.

For example, the stored a plurality of instructions may cause thewireless device to decide not to declare the RLF for the serving cellbased on that the second BWP is activated.

For example, the stored a plurality of instructions may cause thewireless device to deactivate the first BWP upon detecting the radiolink problem on the first BWP.

According to some embodiment of the present disclosure, the stored aplurality of instructions may cause the wireless device to detect aradio link problem on the second BWP. The stored a plurality ofinstructions may cause the wireless device to decide whether to declarethe RLF for the serving cell based on radio link state of the secondBWP. The stored a plurality of instructions may cause the wirelessdevice to declare the RLF for the serving cell.

For example, the stored a plurality of instructions may cause thewireless device to initiate a recovery procedure upon declaring the RLFfor the serving cell.

For example, the RLF for the serving cell may be decided based on radiostate of all of activated BWPs for the serving cell.

According to some embodiments of the present disclosure, the stored aplurality of instructions may cause the wireless device to perform atransmission to inform the network of the radio link problem on thefirst BWP. For example, the transmission may be performed on the secondBWP.

According to some embodiments of the present disclosure, the radio linkproblem on the first BWP may be detected upon detecting that measurementresult of the first BWP is lower than a threshold.

According to some embodiments of the present disclosure, the radio linkproblem on the first BWP may be detected upon receiving, by an upperlayer of the wireless device, consecutive “out-of-sync” indications froma physical layer of the wireless device.

According to some embodiments of the present disclosure, the stored aplurality of instructions may cause the wireless device to start a radiolink problem timer upon detecting a physical layer problem on the firstBWP.

In this case, the radio link problem on the first BWP may be detectedupon detecting expiry of the radio link problem timer.

For example, the radio link problem timer may be configured for each ofthe first BWP and the second BWP, respectively.

According to some embodiments of the present disclosure, the stored aplurality of instructions may cause the wireless device to be incommunication with at least one of a user equipment, a network, or anautonomous vehicle other than the wireless device.

Hereinafter, a method for declaring radio link failure in multipleactive bandwidth parts performed by a base station (BS) in a wirelesscommunication system, according to some embodiments of the presentdisclosure, will be described.

The BS may activate a first bandwidth part (BWP) and a second BWP for awireless device.

The BS may receive, from the wireless device, an information informingthat a radio link problem is detected on the first BWP, wherein theinformation is transmitted by the second

BWP.

The BS may change an active BWP from the first BWP to the third BWP. Forexample, the BS may deactivate the first BWP and activate a third BWP.

Hereinafter, a base station (BS) for declaring radio link failure inmultiple active bandwidth parts in a wireless communication system,according to some embodiments of the present disclosure, will bedescribed.

The BS may include a transceiver, a memory, and a processor operativelycoupled to the transceiver and the memory.

The processor may be configured to activate a first bandwidth part (BWP)and a second BWP for a wireless device.

The processor may be configured to control the transceiver to receive,from the wireless device, an information informing that a radio linkproblem is detected on the first BWP, wherein the information istransmitted by the second BWP.

The processor may be configured to change an active BWP from the firstBWP to the third BWP upon receiving the transmission. For example, theprocessor may be configured to deactivate the first BWP and activate athird BWP.

The present disclosure can have various advantageous effects.

According to some embodiments of the present disclosure, a wirelessdevice could declare radio link failure in multiple active bandwidthparts efficiently.

For example, a wireless device could avoid the service interruption timerequired to recover the radio link failure when multiple BWPs areactivated.

For example, a wireless device could declare the radio link failureefficiently only when there is no available active BWP.

For example, a wireless device could change the active BWP efficientlyby informing network of the problematic BWP only when there is noavailable active BWP.

According to some embodiments of the present disclosure, a wirelesscommunication system could provide an efficient solution to a wirelessdevice for declaring radio link failure in multiple active bandwidthparts.

Advantageous effects which can be obtained through specific embodimentsof the present disclosure are not limited to the advantageous effectslisted above. For example, there may be a variety of technical effectsthat a person having ordinary skill in the related art can understandand/or derive from the present disclosure. Accordingly, the specificeffects of the present disclosure are not limited to those explicitlydescribed herein, but may include various effects that may be understoodor derived from the technical features of the present disclosure.

Claims in the present disclosure can be combined in a various way. Forinstance, technical features in method claims of the present disclosurecan be combined to be implemented or performed in an apparatus, andtechnical features in apparatus claims can be combined to be implementedor performed in a method. Further, technical features in method claim(s)and apparatus claim(s) can be combined to be implemented or performed inan apparatus. Further, technical features in method claim(s) andapparatus claim(s) can be combined to be implemented or performed in amethod. Other implementations are within the scope of the followingclaims.

1. A method performed by a wireless device in a wireless communicationsystem, the method comprising, activating a first bandwidth part (BWP)and a second BWP for a serving cell; performing a radio link monitoring(RLM) on the first BWP and the second BWP; detecting a radio linkproblem on the first BWP; and deciding whether to declare a radio linkfailure (RLF) for the serving cell based on radio link state of both thefirst BWP and the second BWP.
 2. The method of claim 1, wherein themethod further comprises, deciding not to declare the RLF for theserving cell based on that the second BWP is activated.
 3. The method ofclaim 1, wherein the method further comprises, deactivating the firstBWP upon detecting the radio link problem on the first BWP.
 4. Themethod of claim 3, wherein the method further comprises, detecting aradio link problem on the second BWP; deciding whether to declare theRLF for the serving cell based on radio link state of the second BWP;and declaring the RLF for the serving cell.
 5. The method of claim 4,wherein the method further comprises, initiating a recovery procedureupon declaring the RLF for the serving cell.
 6. The method of claim 1,wherein the RLF for the serving cell is decided based on radio state ofall of activated BWPs for the serving cell.
 7. The method of claim 1,wherein the method further comprises, performing a transmission toinform the network of the radio link problem on the first BWP.
 8. Themethod of claim 7, wherein the transmission is performed on the secondBWP.
 9. The method of claim 1, wherein the radio link problem on thefirst BWP is detected upon detecting that measurement result of thefirst BWP is lower than a threshold.
 10. The method of claim 1, whereinthe radio link problem on the first BWP is detected upon receiving, byan upper layer of the wireless device, consecutive “out-of-sync”indications from a physical layer of the wireless device.
 11. The methodof claim 1, wherein the method further comprises, starting a radio linkproblem timer upon detecting a physical layer problem on the first BWP.12. The method of claim 11, wherein the radio link problem on the firstBWP is detected upon detecting expiry of the radio link problem timer.13. The method of claim 11, wherein the radio link problem timer isconfigured for each of the first BWP and the second BWP, respectively.14. The method of claim 1, wherein the wireless device is incommunication with at least one of a user equipment, a network, or anautonomous vehicle other than the wireless device.
 15. A wireless devicein a wireless communication system comprising: a transceiver; a memory;and at least one processor operatively coupled to the transceiver andthe memory, and configured to: activate a first bandwidth part (BWP) anda second BWP for a serving cell; perform a radio link monitoring (RLM)on the first BWP and the second BWP; detect a radio link problem on thefirst BWP; and decide whether to declare a radio link failure (RLF) forthe serving cell based on radio link state of both the first BWP and thesecond BWP.
 16. The wireless device of claim 15, wherein the at leastone processor is further configured to, decide not to declare the RLFfor the serving cell based on that the second BWP is activated.
 17. Thewireless device of claim 15, wherein the at least one processor isfurther configured to, deactivate the first BWP upon detecting the radiolink problem on the first BWP.
 18. The wireless device of claim 17,wherein the at least one processor is further configured to, detect aradio link problem on the second BWP; decide whether to declare the RLFfor the serving cell based on radio link state of the second BWP; anddeclare the RLF for the serving cell.
 19. The wireless device of claim18, wherein the at least one processor is further configured to,initiate a recovery procedure upon declaring the RLF for the servingcell. 20-29. (canceled)
 30. A non-transitory computer-readable mediumhaving stored thereon a plurality of instructions, which, when executedby a processor of a wireless device, cause the wireless device to:activate a first bandwidth part (BWP) and a second BWP for a servingcell; perform a radio link monitoring (RLM) on the first BWP and thesecond BWP; detect a radio link problem on the first BWP; and decidewhether to declare a radio link failure (RLF) for the serving cell basedon radio link state of both the first BWP and the second BWP. 31-32.(canceled)